Russian President Vladimir Putin has met with UN-Arab League special envoy Kofi Annan to discuss the deteriorating situation in Syria.
Putin pledged to "do everything" to support Annan's task to mediate an end to hostilities and encourage a dialogue between the Syrian government and factions opposed to the rule of President Bashar al-Assad.
"From the very beginning, and you know that, from your very first steps as the UN and as Arab League envoy, we have been supporting, and we are supporting your efforts aimed at restoring peace in Syria," Putin said. "We all know you as an honest and professional man, a man who enjoys a very high popularity. I want to assure you that we will do everything we can to support your efforts."
Annan, whose mission has been largely unsuccessful so far, said the Syrian crisis has reached a "crossroads."
Annan said he was sorry to return to Moscow during such a "tragic occasion" in Syria and expressed the hope he would come back to Moscow "when I don't have such heavy responsibilities on my shoulders."
Russia has repeatedly rejected international efforts to pressure the Assad regime and Annan's visit came ahead of a move by some Western nations to hold a vote on a UN Security Council resolution to impose sanctions against the Syrian government.
Russia has already made clear it would block the measure as it has two previous resolutions threatening penalties against Assad's regime.
Despite Russian support for Assad, Syrian rebel groups have managed to make advances and some rebel forces are now fighting on the outskirts of the capital, Damascus.
Syria's Army reportedly was using helicopters to battle opposition forces in at least four Damascus neighborhoods -- an escalation of the most serious fighting in the capital since the uprising against Assad began 16 months ago.
Government troops already had been using tanks and rockets in the fighting on the south side of Damascus, which started last weekend.
Opposition fighters in the Free Syrian Army announced what they called a full-scale attack operation against regime forces.
Activists believe more than 17,000 people have been killed in Syria since violence broke out last year.
With reporting by ITAR-TASS, Interfax, AFP, AP, and dpa