Syrian President Bashar Al Assad's regime will not stay in power for much longer, Arab League chief Nabil Al Arabi said on Wednesday, Nov 7, urging the opposition meeting in Qatar to put aside their differences, The Gulf Today reported.

"It is important to unify the opposition's visions, especially because everyone knows that the regime in Syria will not remain for long and one day there will be a new situation in Syria," he told reporters in Cairo.

Meanwhile, Syrian rebels made a new push into Damascus, clashing heavily with troops in the rebellious suburbs of the capital and firing mortars into the sprawling Palestinian refugee camp, activists said.

In recent days, opposition fighters also stepped up assaults on high-ranking supporters of Assad in the capital.

The rebels also have been trying to break the resistance of a pro-government Palestinian faction, which could drag the half million Palestinian refugees in Syria into the civil war.

The new challenge from rebels in the capital comes as the U.S. and Britain take steps to bolster the fragmented Syrian opposition.

British Prime Minister David Cameron said his government planned to change its policy and deal directly with opposition military leaders. Previously, Britain has had contacts only with exile groups and political opposition figures inside Syria.

He urged newly re-elected President Barack Obama to join the Britain in opening direct talks with rebel fighters, and said they must do more to end the civil war that has killed more than 36,000, according to activists' tallies.