The United States voiced fears that Syria's government is planning a new massacre, as regime helicopters fired on rebel stronghold towns and raging violence killed nearly 90 people on Monday.

On the political front, the newly elected leader of Syria's exiled opposition urged President Bashar al-Assad to hand over power to his deputy Faruq al-Shara, in line with a plan based on a U.N.-backed power transfer in Yemen.

The United States has withdrawn negotiators from Pakistan after talks failed to produce an agreement on reopening vital NATO supply routes into Afghanistan, the Pentagon said Monday.

"The decision was reached to bring the team home for a short period of time," Pentagon spokesman George Little told reporters.

The United States welcomed on Monday all efforts exerted by Lebanese leaders to strengthen the national unity and stability in the country.

“We encourage the participants in the national dialogue to engage constructively,” the U.S. embassy said via twitter.

Russia will not approve the use of force against the Syrian regime at the United Nations, Foreign Minister Sergei Lavrov said Saturday at a briefing in Moscow.

"We will not sanction the use of force at the United Nations Security Council," Lavrov said in televised remarks as he gave a briefing on Russia's proposal for an international conference on Syria.

U.S. President Barack Obama hit back Friday at accusations that the White House was somehow involved in leaking classified national security secrets, labeling the allegations "offensive."

Lawmakers have fumed this week over a series of news reports, some quoting anonymous administration officials, that reveal details of covert U.S. operations. Some Republicans have suggested they were done in order to boost Obama's image of a tough commander-in-chief in an election year.

Myanmar on Friday called for sanctions imposed on the country to be completely lifted as they are hurting efforts to attract foreign investment amid a historic reform drive.

U Ko Ko Hlaing, chief political advisor to President Thein Sein, said that without fuller access to the Southeast Asian nation companies were adopting a "wait and see" attitude.

France on Thursday condemned Israeli plans to expand a West Bank settlement by 300 homes and urged Prime Minister Benjamin Netanyahu not to follow through with their construction.

"We call on Prime Minister Benjamin Netanyahu to abstain from implementing these plans. We recall that colonization in all its forms is illegal under international law, undermines the two-state solution at ground level and is an obstacle to peace," foreign ministry spokesman Bernard Valero said.

U.S. Secretary of State Hillary Clinton on Thursday condemned the latest onslaught of violence sponsored by the regime in Syria and said President Bashar Assad had to go.

"The regime-sponsored violence that we witnessed in Hama yesterday (Wednesday) is simply unconscionable," she told reporters.

Al-Qaida is still a serious and imminent threat as it is spreading geographically, U.S. Secretary of State Hillary Clinton said Thursday.

"The core of al-Qaida that carried out the 9/11 attacks may be on the path to defeat, but the threat has spread, becoming more geographically diverse," Clinton said ahead of a counterterrorism meeting.

Pentagon chief Leon Panetta said Wednesday that the U.S. would continue to attack al-Qaida in Pakistan despite complaints from Islamabad that the drone strikes violate its sovereignty.

"We have made it very clear that we are going to continue to defend ourselves," Secretary of Defense Leon Panetta said in India a day after the U.S. announced the killing of al-Qaida's number two Abu Yahya al-Libi.