President Bashar al-Assad's promises to Russia to work towards ending bloodshed in Syria were merely manipulation and should not be believed, French Foreign Minister Alain Juppe said Wednesday.

"I absolutely do not believe in the commitments made by the Syrian regime," he told a radio programme jointly run by AFP. "This is a manipulation which we are not going to fall for."

Russian Foreign Minister Sergei Lavrov met Tuesday with Assad in Damascus and afterwards said the leader was "fully committed" to ending the violence, even as regime tanks continued to pound the protest city of Homs.

Lavrov said Russia was prepared to work to end the crisis under a peace plan put forward by the Arab League and that Assad was ready for dialogue with all political forces.

He did not specify whether he was referring to the latest Arab League plan calling for Assad to step down or a November plan which called for an observer mission and an end to violence.

Moscow sparked Western anger last week by joining Beijing in using its veto at the Security Council to block UN action against the Damascus regime, in what US Secretary of State Hillary Clinton called a "travesty."

Syrian government forces kept up their relentless assault on Homs on Wednesday, with dozens of civilians reported killed.

Syria has been in turmoil for almost a year, after pro-democracy protests erupted as part of the Arab Spring series of revolts in the region. Human rights groups estimate that at least 6,000 people have been killed.