William Hague says the UK and US remain “closely aligned” on Syria, after talks with his US counterpart John Kerry.
The UK foreign secretary said the two were working together to save lives and revive peace talks as well as press for a strong response to the Assad government’s use of chemical weapons.
Mr Kerry said the risks of doing nothing were greater than acting.
The two countries remained “true friends” despite the UK ruling out any military involvement, he insisted.
Their meeting in London comes as the US tries to gather support for military strikes.
UK Prime Minister David Cameron has said that Parliament’s vote last month means the UK will not join the US in any military action in response to Syria’s suspected use of chemical weapons.