Here is a timeline of events since a chemical weapons attack took place near the Syrian capital Damascus on August 21.
-- AUGUST 2013 --
- 21: Syrian troops launch an offensive in the Ghouta suburb of Damascus. The opposition accuses the army of chemical weapons strikes east and southwest of the capital, including one in Moadamiyet al-Sham, that killed more than 1,300 people.
The Syrian government denies the claims and the United Nations calls for a probe.
Videos posted on the Internet show medics attending to suffocating children and hospitals being overwhelmed.
- 22: International pressure mounts on Syria to allow UN experts present there since August 18 to investigate the chemical claims.
- 23: UN Secretary General Ban Ki-moon says chemical attack would constitute "crime against humanity."
Britain and France accuse Syrian regime for alleged chemical attack as the United States mulls possible military strikes on government targets.
- 26: Russia warns military intervention without UN Security Council approval. Foreign Minister Sergei Lavrov says the West has no proof to back claims Syria's regime used chemical weapons.
- 29: British lawmakers vote against military action in Syria.
- 30: A US intelligence report blames Syria's government for the attack with "high confidence" and says that 1,429 people were killed, including 426 children.
- 31: US President Barack Obama says he will ask the US Congress to authorise military action against Syria.
- 6: Obama and Russian President Vladimir Putin fail to end their dispute at a meeting of the Group of 20 richest nations. Eleven G20 states call for a "strong international response" to the attack they say was clearly carried out by the Syrian regime.
- 9: Lavrov calls on the Assad regime to hand over control of its chemical weapons arsenal to international supervision to head off military action. Syrian Foreign Minister Walid Muallem welcomes the call but the opposition dismisses it as a "political manoeuvre".
- 14: The UN formally accepts Syria's application to join the convention banning chemical weapons.
- 14: The United States and Russia agree on a plan to eliminate Syria's chemical weapons by the middle of 2014.
- 16: A UN reports says there is clear evidence that sarin gas was used in the August 21 attack.
- 21: The Hague-based Organisation for the Prohibition of Chemical Weapons says Syria has handed over complete data on its chemical arsenal, meeting a deadline to avert military strikes.
- 26: The United States and Russia agree a draft UN Security Council resolution on destroying Syria's chemical weapons ending days of deadlock.
- 27: UN experts start probing seven alleged chemical weapons attacks in Syria.