US Secretary of State Hillary Clinton was planning to meet with Russian Foreign Minister Sergei Lavrov here Saturday in a bid to clinch Russian support for a strong UN resolution on Syria.

The talks on the sidelines of the Munich Security Conference are expected before the UN Security Council meets in New York for what a diplomat said will be a vote on a resolution condemning the violent repression in Syria.

"She'll have a bilateral (meeting) with Russian Foreign Minister Lavrov," a senior State Department official told reporters on the condition of anonymity during the flight from Washington to Munich.

"You can be sure that Syria and the discussions at the UN will be one of the issues there, among many," the official said.

Another State Department official, who also spoke on the condition of anonymity, said "there's more work to do" after Clinton spoke by phone to Lavrov on the flight Friday to Munich.

The official said Clinton wanted to talk to Lavrov "because we are interested in getting to a vote as quickly as we can."

In Washington, State Department deputy spokesman Mark Toner described the Clinton-Lavrov phone call as "constructive," amid a US push for passage of the resolution.

The latest draft seen by AFP does not explicitly call on Syrian President Bashar al-Assad to step down or mention an arms embargo or sanctions, though it "fully supports" an Arab League plan to facilitate a democratic transition.

"We're cautiously optimistic we're going to get a very strong show of support for this resolution," a senior State Department official said Friday.

The latest attempt at consensus emerged after an impasse in the UN Security Council, with Russia leading the opposition to a tougher draft resolution authored by Western powers and the Arab League.

Russia, a long-standing Assad ally and one of his top arms suppliers, declared that the UN body does not have the authority to impose a resolution that calls for regime change in Syria, a position supported by China.

The new draft backs the January 22 Arab League request that Assad transfer power to a deputy and a government of national unity within two months but does not call on him to step down, according to a copy obtained by AFP.

Instead, it calls for a "Syrian-led political transition to a democratic, plural political system... including through commencing a serious political dialogue between the Syrian government and the whole spectrum of the Syrian opposition..."

In Washington on Wednesday, Clinton said UN Security Council member countries must decide whether to side with the Syrian people or a "brutal dictatorial regime," framing it as a historic choice.

Observers said more than 6,000 people have died since a pro-democracy movement rose up in Syria in March last year, inspired by similar movements in Tunisia and Egypt.