Barack Obama says the US has concluded that the Syrian government carried out a chemical weapons attacks near Damascus.
He said the use of chemical weapons affected US national interests and sending a "shot across the bows" could have a positive impact.
But he said he had not yet made a decision about whether to intervene militarily.
His comments follow a day of behind-the-scenes wrangling at the UN.
http://www.bbc.co.uk/news/world-middle-east-23875121
