Here's a timeline to date:
First UN Security Council draft resolution proposed by France, the United Kingdom, and the United States:
"Recalling the Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare, and the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction (CWC) ratified by the Syrian Arab Republic on 14 September 2013, and the Council's resolutions 1540 (2004), 2118 (2013), 2209 (2015), 2235 (2015), 2314 (2016), and 2319 (2016),
Expressing its horror at the reported use of chemical weapons in the Khan Shaykhun area of southern Idlib in the Syrian Arab Republic on 4 April 2017 causing large-scale loss of life and injuries, affirming that the use of chemical weapons constitutes a serious violation of international law, and stressing that those responsible for any use of chemical weapons must be held accountable,
Noting the Organisation for the Prohibition of Chemical Weapons (OPCW) has announced, in addition to its ongoing investigation, that its Fact Finding Mission (FFM) is in the process of gathering and analysing information on this incident from all available sources and will report to the OPCW Executive Council,
Recalling that in resolution 2118 (2013) the Council decided that the Syrian Arab Republic shall not use, develop, produce, otherwise acquire, stockpile or retain chemical weapons or transfer, directly or indirectly, chemical weapons, to other States or non-State actors and underscored that no party in Syria should use, develop produce acquire, stockpile, retain or transfer chemical weapons,
Recalling its determination that the use of chemical weapons in the Syria Arab Republic represents a threat to international peace and security,
1. Condemns in the strongest terms the reported use of chemical weapons in the Syrian Arab Republic, in particular the attack on Khan Shaykhun reported on 4 April 2017, expresses its outrage that individuals continue to be killed and injured by chemical weapons in the Syrian Arab Republic, and expresses its determination that those responsible must be held accountable;
2. Expresses its full support to the OPCW Fact Finding Mission, demands that all parties provide delay-free and safe access to any sites deemed relevant by the OPCW FFM, and, as applicable, by the JIM, to the reported incident in Khan Shaykhun in accordance with resolution 2118, and requests that the FFM report the results of its investigation as soon as possible;
3. Requests that the Secretary General make the necessary arrangements for the UN-OPCW Joint Investigative Mechanism to liaise closely with the Fact Finding Mission to expeditiously investigate any incident the FFM determines involved or likely involved the use of chemicals as weapons in order to identify those involved in accordance with the provisions of paragraph 5 of its Resolution 2235;
4. Recalls that in its resolutions 2118 and 2235 it decided that the Syrian Arab Republic and all parties in Syria shall cooperate fully with the OPCW and the United Nations including the Joint Investigation Mechanism;
5. Emphasises that this includes the obligation upon the Syrian Arab Republic to provide the JIM and FFM with the following and take the following steps:
(a) flight plans, flight logs, and any other information on air operations, including all flight plans or flight logs filed on April 4 2017;
(b) names of all individuals in command of any helicopter squadrons;
(c) arrange meetings requested including with generals or other officers, within no more than five days of the date on which such meeting is requested;
(d) immediately provide access to relevant air bases from which the JIM or the FFM believe attacks involving chemicals as weapons may have been launched
6. Requests the Secretary-General to report on whether the information and access described in paragraph 5 has been provided in his reports to the Security Council every 30 days pursuant to paragraph 12 of resolution 2118.
7. Recalls its decision in response to violations of resolution 2118 to impose measures under Chapter VII of the United Nations charter."
Second UN Security Council draft resolution proposed by the Russian Federation:
"Recalling the Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare, and the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction (CWC) ratified by the Syrian Arab Republic on 14 September 2013, and the Council's resolutions 1540 (2004), 2118 (2013), 2209 (2015), 2235 (2015), 2314 (2016), and 2319 (2016),
Expressing its deep concern regarding the alleged incident with the chemical weapons in the Khan Shaykhun area of southern Idlib in the Syrian Arab Republic in 4 April 2017 reportedly causing large-scale loss of life and injuries, affirming that the use of chemical weapons constitutes a serious violation of international law, and stressing that those responsible for any use of chemical weapons must be held accountable,
Recalling that in resolution 2118 (2013) the Council decided that the Syrian Arab Republic shall not use, develop, produce, otherwise acquire, stockpile or retain chemical weapons or transfer, directly or indirectly, chemical weapons, to other States or non-State actors and underscored that no party in Syria should use, develop, produce, acquire, stockpile, retain or transfer chemical weapons,
1.Requests the joint FFM and the JIM investigative team to visit as soon as possible the site of the alleged incident in Khan Shaykhun and adjacent territories to conduct full-scale investigation using the whole spectrum of relevant methods, including the alternative information collection efforts and investigative skills, as was strongly recommended for such cases in the 4th and 5th JIM's reports (para. 49 and para . 11 respectively).
2.Demands all parties in the Syrian Arab Republic to secure in accordance with the resolution 2118 (2013) without any delay free and safe access for the joint FFM and JIM team to the site of the incident and adjacent areas;
3.Requests the Director-General of the OPCW Technical Secretariat and the head of the OPCW-UN Joint Investigative Mechanism (JIM) to forward through the United Nations Secretary-General to the Council for its consideration their proposals on the personal composition of the joint team to be dispatched to the Idlib Governorate of the Syrian Arab Republic based on the principle of a broad-based and balanced geographical representation;
4.Decides that the report of the joint FFM and JIM team should include all the evidences collected at the site of the incident and be provided to the Council for consideration;
5.Decides to remain actively seized of the matter."
Third UN Security Council draft resolution proposed by Bolivia, Egypt, Ethiopia, Italy, Japan, Kazakhstan, Senegal, Sweden, Ukraine, and Uruguay:
"Recalling the Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare, and the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction (CWC) ratified by the Syrian Arab Republic on 14 September 2013, and the Council's resolutions 1540 (2004), 2118 (2013), 2209 (2015), 2235 (2015), 2314 (2016), and 2319 (2016),
Expressing its horror at the reported use of chemical weapons in the Khan Shaykhun area of southern Idlib in the Syrian Arab Republic on 4 April 2017 causing large-scale loss of life and injuries, affirming that the use of chemical weapons constitutes a serious violation of international law, and stressing that those responsible for any use of chemical weapons must be held accountable,
Noting the Organisation for the Prohibition of Chemical Weapons (OPCW) has announced, in addition to its ongoing investigation, that its Fact Finding Mission (FFM) is in the process of gathering and analysing information on this incident from all available sources and will report to the OPCW Executive Council,
Recalling that in resolution 2118 (2013) the Council decided that the Syrian Arab Republic shall not use, develop, produce, otherwise acquire, stockpile or retain chemical weapons or transfer, directly or indirectly, chemical weapons, to other States or non-State actors and underscored that no party in Syria should use, develop produce acquire, stockpile, retain or transfer chemical weapons,
Recalling its determination that the use of chemical weapons in the Syria Arab Republic represents a threat to international peace and security,
1. Condemns in the strongest terms the reported use of chemical weapons in the Syrian Arab Republic, in particular the attack on Khan Shaykhun reported on 4 April 2017, expresses its outrage that individuals continue to be killed and injured by chemical weapons in the Syrian Arab Republic, and expresses its determination that those responsible must be held accountable;
2. Expresses its full support to the OPCW Fact Finding Mission, demands that all parties provide delay-free and safe access to any sites deemed relevant by the OPCW FFM, and, as applicable, by the JIM, to the reported incident in Khan Shaykhun in accordance with resolution 2118, and requests that the FFM report the results of its investigation as soon as possible;
3. Requests that the Secretary General make the necessary arrangements for the UN-OPCW Joint Investigative Mechanism to liaise closely with the Fact Finding Mission to expeditiously investigate any incident the FFM determines involved or likely involved the use of chemicals as weapons in order to identify those involved in accordance with the provisions of paragraph 5 of its Resolution 2235;
4. Recalls that in its resolutions 2118 and 2235 it decided that the Syrian Arab Republic and all parties in Syria shall cooperate fully with the OPCW and the United Nations including the Joint Investigation Mechanism;
5. Emphasises that this includes the obligation upon the Syrian Arab Republic of complying with their relevant recommendations, by accepting personnel designated by the OPCW or the United Nations, by providing for and ensuring the security of activities undertaken by these personnel, by providing these personnel with immediate and unfettered access to and the right to inspect, in discharging their functions, any and all sites, and by allowing immediate and unfettered access to individuals that the OPCW has grounds to believe to be of importance for the purpose of its mandate, and decides that all parties in Syria shall cooperate fully in this regard; [op. 7 of op. 2118]
6. Requests the Secretary-General to report on whether the information and access described in paragraph 5 has been provided in his reports to the Security Council every 30 days pursuant to paragraph 12 of resolution 2118.
7. Recalls its decision in response to violations of resolution 2118 to impose measures under Chapter VII of the United Nations charter. "
Reporting on UN Security Council machinations include:
"5:45 a.m. April 7, 2017, Eastern European Time Zone
Russia's deputy U.N. ambassador says the U.S. decision to cancel a vote on a U.N. resolution that would condemn the reported chemical weapons attack on a Syrian town 'opens a window of opportunity' to find a compromise.
Vladimir Safronkov told reporters after closed Security Council consultations that a resolution 'should not, cannot and will not pre-judge the outcome from (an) investigation.'
Russia strongly objected to provisions in the original draft circulated by Britain, France and the United States which it said blamed President Bashar Assad's forces for the attack before an investigation.
Safronkov said he can't understand why the council rejected Russia's proposal for sending a team to conduct an 'impartial, objective, honest investigation.'
...
3:15 a.m. April 7, 2017, Eastern European Time Zone
The United Kingdom says there will be no vote on a U.N. Security Council resolution Thursday night to condemn the reported use of chemical weapons in a northern Syria town that killed more than 80 people.
The British Mission's political coordinator Stephen Hickey tweeted that the vote wouldn't take place because council members are still negotiating the text...
The 10 elected members of the Security Council presented what they hoped would be a compromise text on Thursday that addressed a key Russian objection - spelling out Syrian government obligations to investigators.
...
2:35 a.m. April 7, 2017, Eastern European Time Zone
China's U.N. Ambassador Liu Jieyi says he hopes the U.N. Security Council can reach consensus on a resolution condemning this week's reported use of chemical weapons in northern Syria.
He spoke before heading into closed council consultations Thursday evening. The U.S. Mission said it was hoping for a vote late Thursday.
The latest text being discussed expresses 'horror' at Tuesday's attack in Khan Sheikhoun that caused 'large-scale loss of life.' It demands that all parties provide 'delay-free' and safe access to all sites that investigators from the international chemical weapons watchdog and the U.N. want to visit.
A compromise text put forward by the 10 elected members of the council would drop five specific requirements for the Syrian government to provide investigators, including flight plans and logs for April 4th when Khan Sheikhoun was attacked, names of commanders of helicopter squadrons, and access to air bases where investigators believe attacks involving chemical weapons may have been launched.
Instead, that text would be replaced with exact language from the September 2013 resolution that condemned a Syrian chemical weapons attack the previous month in the Damascus suburb of Ghouta that killed hundreds of civilians.
The proposed new language would order the Syrian government to cooperate fully with the Organization for the Prohibition of Chemical Weapons and the U.N. and provide their investigators 'immediate and unfettered access' and 'the right to inspect ... any and all sites.' It would also orders all parties in Syria to 'cooperate fully.'
...
9:45 p.m. April 6, 2017, Eastern European Time Zone
German Chancellor Angela Merkel...criticized the failure of the U.N. Security Council to pass a resolution condemning the attack.
She said those who refused to back the resolution 'should think about what responsibility they are shouldering.'
...
8:15 p.m. April 6, 2017, Eastern European Time Zone
The United States says it hopes for a vote late Thursday on a resolution that would condemn the chemical attack in northern Syria that killed dozens of people.
The U.S. currently holds the presidency of the U.N. Security Council and drafted a resolution along with Britain and France that condemns the use of chemical weapons, particularly in Tuesday's attack on Khan Sheikhoun, 'in the strongest terms.'...
A spokesman for the U.S. mission to the United Nations said 'we're hoping to get a vote done later today.'
France's U.N. Ambassador Francois Delattre told reporters Thursday that 'we need a robust text,' adding that 'there are fundamentals we cannot compromise with when it's about the barbaric murder of civilians, among them many children, with chemical weapons.'
Delattre told The Associated Press he thought there was "still a chance" for an agreement with Russia.
...
6:30 p.m. April 6, 2017, Eastern European Time Zone
The U.N. children's agency says at least 27 children were among the more than 80 people killed in the suspected chemical attack in northern Syria.
UNICEF says another 546 people, including many children, were wounded in Tuesday's attack on the town of Khan Sheikhoun, and that casualty figures are expected to rise.
...
2:30 p.m. April 6, 2017, Eastern European Time Zone
The top humanitarian aid official with the U.N.'s Syria office says he believes an awareness of the need to protect civilians is 'sinking in' after a deadly chemical weapons attack this week in Syria's northern Idlib province.
Jan Egeland expressed hopes for a 'watershed moment' with 'all of these world leaders saying that say they have again woken up to the suffering of the civilians that we see every day.'
...
1:35 p.m. April 6, 2017, Eastern European Time Zone
British Foreign Minister Boris Johnson says he cannot understand how anyone on the U.N. Security Council could fail to sign up to a resolution condemning the chemical weapons attack this week that killed dozens in northern Syria.
Johnson said on Thursday during a visit to Sarajevo that he 'cannot understand how anybody on the U.N. Security Council could fail to sign up to a motion condemning the actions of the (Assad) regime that is almost certainly responsible for that crime.'...
He says 'work is now going on in New York on the exact language (of the resolution) and I think we should have no hesitation in forcing it to a vote.'
Russia argued at a U.N. Security Council meeting on Wednesday against holding Assad's government responsible, with Moscow insisting a Syrian air strike had hit a rebel ammunition store that held chemical weapons.
...
11:45 a.m. April 6, 2017, Eastern European Time Zone
France's foreign minister...Jean-Marc Ayrault told CNews television on Thursday that a new U.N. resolution and Syrian peace negotiations should be a top priority - not rushing into new military interventions.
Ayrault says that 'France is still seeking to talk with its partners on the Security Council ... Russia in particular.'
Russia argued at a U.N. Security Council meeting on Wednesday against holding Assad's government responsible for a chemical weapons attack this week that killed more than 80 people in Idlib province.
The U.S. ambassador to the United Nations, Nikki Haley, warned that the Trump administration would take action if the Security Council did not..."