US Defence Secretary Chuck Hagel says Syria is a "fluid situation... we're rethinking options... yes, of course we are". Defence Secretary Philip Hammond at the Pentagon says, "We believe the Assad regime retains control of its chemical weapons".
More top news
Nasa has begun its countdown for a mission to discover whether life might exist on Jupiter's moon Europa.
A mosaic of American film legend Clint Eastwood made from thousands of bullet cases has been created to mark his 85th birthday tomorrow.
Former Lib Dem leader Nick Clegg is among 89 European Union politicians and other senior figures who have been banned from entering Russia.