Kofi Annan, the joint United Nations-Arab League envoy to Syria, has entered talks with US Secretary of State Hillary Clinton to discuss putting "additional pressure" on the government in Damascus.
Annan said on Friday that "everyone is looking for a solution" but acknowledged doubts about a peace deal he brokered, which calls for a ceasefire and dialogue to end more than a year of violence aimed at toppling Syrian President Bashar al-Assad.
"Some say the plan may be dead. Is the problem the plan or the problem is implementation? If it's implementation, how do we get back on track? And if it is the plan, what other options do we have," he asked.
Diplomats in New York said Britain, France and the United States were drawing up a Security Council resolution proposing sanctions against Syria.
"We will move fast to press for a resolution," a UN diplomat told AFP. "There will be action in the coming days to get a vote on a resolution which includes measures under Chapter VII of the UN Charter - which would mean sanctions," the diplomat added in comments confirmed by other Security Council envoys.
Chapter VII allows for sanctions and, in extreme cases, military action. Russia and China, infuriated by the NATO campaign in Libya last year, have vowed to oppose any military intervention.
The three Western permanent members of the council want a new campaign for sanctions after Annan said on Thursday that the international community must warn Assad of "clear consequences" if he does not carry out his commitment to the peace plan.
In Moscow, Clinton's point man on Syria, Fred Hof, met Russian diplomats in a bid to persuade Russia to back Assad's removal. But Mikhail Bogdanov, the Russian deputy foreign minister said after the meeting that Moscow had no information about a leadership change being planned in Damascus and pointedly failed to make any public call for one.
"I do not know anything about such plans by the Syrian president," Bogdanov told state news agency RIA Novosti.
Annan has said he was in discussions to set up an international contact group on the Syria crisis and that he hoped Iran, a close ally of Damascus, would be part of the "solution."
France also backs the bid for a new contact group, a foreign ministry spokesman in Paris said, but diplomats added that Paris like Washington was opposed to inviting Iran.