British Prime Minister David Cameron has joined Barak Obama in warning Syria that any planned use or threat of use of their chemical weapons stockpile would be ‘completely unacceptable’.
A Downing Street official said that the two leaders spoke on the telephone and said that if Assad made such a move it "would force them to revisit their approach so far”.
Mr Cameron also discussed ways to increase support to the Syrian opposition with French president Francois Hollande.
They agreed to "work more closely to identify how they could bolster the opposition and help a potential transitional Syrian government after the inevitable fall of Assad".
Russia meanwhile has criticised western nations of doing nothing to urge the opposition to start a dialogue with the Syrian government and instead ‘openly instigating’ armed resistance.