President Barack Obama said he has decided that the United States should take military action against Syria but is seeking congressional authorisation for the use of force in a vote expected after Congress returns to work September 9.
Here's a look at key Syria developments around the world yesterday amid heightened tensions over potential military action:
Israel carried out a joint missile test with the US in the Mediterranean Sea as Washington considers sea-launched strikes against Syria. The defence ministry said it and the US Defence Department carried out a "successful test" in the Mediterranean and on an air force base in central Israel.
Congress will holding its first public hearing about US plans for military intervention in Syria as Obama tries to convince sceptical Americans and their lawmakers about the need to respond to last month's alleged sarin gas attack outside Damascus.
The United Nations refugee agency said more than two million refugees have fled Syria's violence in an exodus that shows no sign of letting up and could destabilise neighbouring countries. Antonio Guterres, head of the Office for the UN High Commissioner for Refugees, said in Geneva that an average of almost 5,000 citizens a day are flowing out of Syria, many of them with little more than the clothes they are wearing.
The news magazine Der Spiegel reported that Germany's Federal Intelligence Service believes Assad's regime was behind the attacks. German Chancellor Angela Merkel said a united international response to the alleged use of chemical weapons in Syria is unlikely but "the smallest chance" must be used to achieve one. Germany has said it won't participate in any military intervention. It is pushing for action by the long-deadlocked UN Security Council.
Foreign Minister Luiz Alberto Figueiredo said any military intervention against Syria would be seen as a violation of international law unless the UN Security Council gives approval or if the intervention is for self-defence coupled with a UN resolution.