US Secretary of State John Kerry is in London in a bid to garner further support for a tough international response against Syria for an alleged chemical weapons attack last month.
He is due to hold talks with Britain’s Foreign Secretary William Hague before returning to Washington.
Although the UK’s parliament has voted against participating in military strikes, Hague has stressed the need to deter chemical weapons use.
The US claims more than 1400 people died in a gas attack in Damascus and blames the Syrian government. President Bashar al-Assad denies using chemical weapons against his own people.
Passage by Congress on the authorisation of force begins Monday but is by no means certain.
Californian Democrat Loretta Sanchez is leaning towards not approving the military action against Syria: “The minute that one of those cruise missiles lands in there, we are in the Syrian war. It’s a civil war and we are taking sides with the rebels, many of whom are still associated with al Qaeda, and other groups that mean to undermine us. So for the president to say this is just a very quick thing and we’re out of there…. that’s how long wars start,” she said.
A war-weary American public is also questioning the legitimacy of the action. France which has said it will support US-led punitive strikes is still pushing for a UN mandate and could seek a resolution at the Security Council despite previous Russian and Chinese vetoes.