Boris Johnson will today host talks with Western powers to consider "all options" for ending the bloodshed in Syria after fresh discussions between the United States and Russia ended without a solution.
On Saturday, US secretary of state John Kerry met Russian foreign minister Sergei Lavrov and envoys from the major Middle Eastern players in the civil war for talks in Lausanne, Switzerland, which lasted four and a half hours.
Mr Kerry said the discussions focused on "trying to find something that works other than military action" and that minsters offered suggestions that "really might be able to shape some different approaches", although no concrete steps were taken.
He will fly to London to meet the Foreign Secretary, who has said it is time to consider "more kinetic options" including "military options" as Syrian regime forces and their Russian backers continue to pound rebel-held areas of Aleppo.
President Bashar Assad has said he wants to recapture the northern city's rebel-held eastern areas to provide the regime with a "springboard" with which to retake other areas of the country.
On Thursday, Mr Johnson said the US-Russia dialogue aimed at brokering a ceasefire appeared to have "run out of road" and there was a need to find an alternative way forward.
His comments followed cross-party calls from MPs for the establishment of a no-fly zone to end the air strikes on Aleppo, although the Foreign Secretary said they had to be "realistic" about what could be done.
With time running out for the Obama administration and the US in the grip of an extraordinarily bitter presidential election, he acknowledged it may be some time before Washington was ready for a new initiative.
Representatives from Germany, France and Italy will also attend Sunday's summit in London, aiming to reduce the violence and improve humanitarian access.