Syrian rebels could be armed by the UK in a fresh push to oust President Bashar Assad and end the bloodshed after David Cameron ordered officials to re-examine all options.
A Downing Street official said the Prime Minister wanted to put previously rejected measures "back on the table" amid frustration at the failure to halt the 20-month conflict.
Mr Cameron had vowed to redouble his efforts after visiting a refugee camp in Jordan and hearing "horrendous" stories of some of those who have fled the violence.
British diplomats are already set for talks with opposition military commanders as part of the renewed drive - which the premier said should be a top priority for newly-re-elected US president Barack Obama.
He insisted during a three-day Middle East tour that Britain has no plans at present to directly arm rebel forces, pointing out that it was prohibited under the terms of a European Union arms embargo.
Whitehall officials are said however to be considering whether it could be justified under United Nations resolutions and sounding out potential support within Europe for amending the current restrictions.
Other possibile new approaches are the creation of United Nations-enforced "safe zones" within Syria's own borders for refugees - a move being urged on the UN by neighbouring Turkey.
Meanwhile, Mr Assad says he will "live and die" in Syria. His comments come two days after Mr Cameron suggested that Mr Assad could be allowed safe passage out of the country if that would guarantee an end to the civil war.
Mr Assad, who spoke in English with Russia Today TV, says he is not a puppet of the West. He says: "I am Syrian, made in Syria, and I will live and die in Syria."