British Prime Minister David Cameron said he would support granting Syrian President Bashar al-Assad a safe passage out, if requested, to end the nation's bloodshed, in an interview to be aired Tuesday.

Asked what he would say if Assad asked for a safe exit, Cameron told Saudi-owned Al-Arabiya television: "Done. Anything, anything to get that man out of the country and to have a safe transition in Syria."

"Of course, I would favour him facing the full force of international law and justice for what he's done," he said, according to a transcript of the interview made available to the press.

"I am certainly not offering him an exit plan to Britain but if wants to leave, he could leave, that could be arranged," he added.

Cameron who is on a tour of the Middle East, arrived Tuesday in Saudi Arabia after concluding a two-day visit to the United Arab Emirates.

"I am very frustrated that we can't do more," Cameron said.

"This is an appalling slaughter that is taking place in our world today –  40,000 lives lost already and you can see, on your television screens, night after night, helicopters, airplanes belonging to the Assad regime pounding his own country and murdering his own people," he said.