Hello, and welcome to our live coverage of the crisis in Syria. Western diplomats are trying to build a coalition to support action against the government of Bashar al-Assad, but Russia and China are unlikely to support any action. Meanwhile, weapons inspectors are visiting another site of alleged chemical attacks. Follow us for updates as they happen, expert analysis and colour from BBC correspondents, and comment from you, our readers, of course.
The joint UN-Arab League envoy to Syria, Lakhdar Brahimi, is speaking at a news conference in Geneva.
Mr Brahimi says international law is clear, that a UN Security Council resolution is required for military action.
In recent days, Western diplomats and their allies had seemed to hint that they would take action with or without UN backing. Our legal correspondent Clive Coleman wrote a brief explainer of the issues in international law.
1043 Peter Hart, Limavady, Northern Ireland
emails: Chemical weapons are wholly unacceptable. But do the politicians ever sit back and think about the people they represent and how they feel about escalating military action? Do they really want to risk WW3? Diplomacy has to be given a fair crack.
A convoy of UN weapons inspectors left the Four Seasons hotel in Damascus earlier. On Monday the team abandoned their inspection when they came under fire from unidentified snipers.
1037 Alex Lawrence
emails: We must not take any military action or supply arms to the insurgents. They are composed of various factions, some anti-west. Arms could be well used against us. We must try and get them to come to some sort of a diplomatic solution, Russia must be involved as well. But don't let us get involved in any military action!