Prime Minister David Cameron said there is a "growing body of limited but persuasive information" showing that the Syrian regime has used chemical weapons including sarin.
There is a growing body of limited but persuasive information showing that the regime has used, and continues to use, chemical weapons including sarin. The room for doubt about this continues to diminish. We will continue to take action on every front, working with our allies, backing the opposition, pushing for a political solution.
There is an urgent need to start a proper negotiation to force a political transition and to bring this conflict to an end. I will be flying to Sochi on Friday to meet with President Putin to discuss this issue further.
He said he had spoken with the US Secretary of State John Kerry on his return from Russia, and confirmed he will be meeting President Putin on Friday to discuss the crisis.
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Top temperature 14 Celsius (57 F).