Syria opposition chief invited to Moscow
The head of Syria's main opposition coalition has been invited to Moscow after having his first direct talks with Russia's foreign minister.
Sergei Lavrov and Moaz al-Khatib, who leads Syrian National Coalition, met on the sidelines of an international security conference in Munich.
Moscow is a long-time ally of Syrian President Bashar al-Assad.
Later, Mr Lavrov met US Vice-President Joe Biden and UN special envoy Lakhdar Brahimi.
Mr Biden told the conference it was "no secret" that Moscow and Washington had "serious differences" on issues such as Syria.
But he added: "We can all agree... on the increasingly desperate plight of the Syrian people and the responsibility of the international community to address that plight."
After meeting Mr Lavrov, Mr Khatib said: "Russia has a certain vision but we welcome negotiations to alleviate the crisis. There are lots of details that need to be discussed."
The crisis in Syria urgently requires agreement between Russia and the United States if any UN-backed diplomatic initiative is to make headway, says the BBC's Jonathan Marcus in Munich.
However, our correspondent adds, the two are still as far apart as ever.
Mr Lavrov told the conference Mr Biden's insistence that the Syrian leader step down was counterproductive.
"The persistence of those who say that priority number one is the removal of President Assad - I think it's the single biggest reason for the continued tragedy in Syria," he said.
More than 60,000 people have been killed since the uprising against President Assad began 22 months ago, the UN says.