Foreign Secretary William Hague is to hold fresh talks on Syria with his American and French counterparts.
Mr Hague will travel to Paris for the meeting on Monday with US secretary of state John Kerry and French foreign minister Laurent Fabius, the Foreign Office said.
Mr Kerry has spent two days in Geneva in talks with Russian foreign minister Sergei Lavrov discussing a Russian proposal for President Bashar Assad to give up his chemical weapons for destruction by the international community.
The secretary of state described their talks as "constructive" and said that they would meet again in the margins of the United Nations General Assembly in New York on September 28.
"I will say on behalf of the United States that President (Barack) Obama is deeply committed to a negotiated solution with respect to Syria, and we know that Russia is likewise. We are working hard to find the common ground to be able to make that happen," he said.
"We are committed to try to work together, beginning with this initiative on the chemical weapons, in hopes that those efforts could pay off and bring peace and stability to a war-torn part of the world."
Meanwhile UN secretary-general Ban Ki-moon said he believed a report by UN inspectors due out on Monday would be "an overwhelming report that chemical weapons were used" in an attack last month.
Mr Ban - who was apparently unaware that his comments to the Women's International Forum were being broadcast on UN television - also said that the Assad regime had "committed many crimes against humanity."
"Therefore, I'm sure that there will be surely the process of accountability when everything is over," he said.