David Cameron said evidence the Syrian government has used chemical weapons is "extremely serious" and he will discuss the issue with US President Barack Obama today, according to Reuters.
David Cameron said he has not ruled out stepping up action against the Syrian regime after growing evidence they were using chemical weapons, according to Reuters.
Cameron told NPR radio: "Certainly we haven't ruled out stepping up action in response to what seems to be happening on the ground.
"The evidence is growing; the lack of room for doubt is shrinking, and I think this is extremely serious."
The Prime Minister said he would raise the issue with US President Barack Obama at their meeting today.
David Cameron has begun a meeting with US President Barack Obama in the White House.
The Prime Minister is in America to highlight the benefits of a free trade deal between the EU and US.
The Prime Minister has arrived in Washington, DC, shortly after 11pm local time.
David Cameron will today raise the prospect of using next month's G8 summit in Northern Ireland to launch negotiations for an EU-US trade deal.
Writing in the Wall Street Journal, Mr Cameron said:
When times are tough, some want to put the barriers up, to look inwards, and to protect themselves from the world.
But Britain and America stand for a better way. We have a precious opportunity to transform the global economy - not by less openness and less free trade, but by more. And we must do everything possible to seize it.
Trade is not a zero sum game where one nation's success is another's failure. Trade makes the cake bigger so everyone can benefit. Take the free trade area between Europe and the US on which we hope to launch negotiations when President Obama is in Northern Ireland for the G8 next month.
The Prime Minister will meet with Barack Obama today to discuss trade liberalisation, development and Syria during his three-day visit to America.
The two leaders will be joined in the Oval Office by US secretary of state John Kerry, Mr Cameron's national security adviser Kim Darroch, and opposite number Tom Donilon.
David Cameron will urge a peace conference on Syria by the end of the month, believing that efforts to end the 27 month conflict have gained some momentum after his trip to Sochi for talks with President Vladimir Putin last week, and Mr Kerry's visit to Moscow.
One of the main obstacles to easing the situation has been Russian support for Bashar Assad's regime.
David Cameron will hold talks with Barack Obama today to highlight the benefits for Britain of a free trade deal between the EU and the US.
The Prime Minister will argue that an agreement could be worth up to £10 billion a year to the economy.
Mr Cameron may also need to reassure the president about the UK's future within the grouping.
It comes as Cabinet ministers Michael Gove and Philip Hammond yesterday became the latest senior figures to indicate they would currently vote to leave the EU.