Syria peace mediator Kofi Annan was due in Moscow on Monday for talks with President Vladimir Putin amid growing pressure on Russia to finally back the ouster of President Bashar al-Assad.
The Kremlin said Sunday the UN-Arab League envoy would arrive in Moscow on Monday and meet Putin the following day for talks in which "Russia will underscore its support for the peace plan of Kofi Annan".
"The Russian side proceeds from the premise that this plan is the only viable platform for solving internal Syrian problems," it said in a statement.
Annan was also scheduled to meet Foreign Minister Sergei Lavrov while UN chief Ban Ki-moon travels to China -- a country that along with Russia has blocked two UN Security Council resolutions sanctioning Assad's regime.
A UN spokesman said Ban appealed to China's foreign minister on Saturday for the Asian powerhouse "to use its influence to ensure the full and immediate implementation" of Annan's peace initiative.
It will be Annan's second visit to Moscow since he won support from former president Dmitry Medvedev for his initial six-point peace initiative for the brutal conflict during talks in March.
Russia has firmly resisted any form of outside pressure on Assad to step aside and make way for a transition government that foreign powers agreed on at a meeting in Geneva last month.
Lavrov met last week with the head of the opposition Syrian National Council, without any sign of a change in his stance on ways to resolve the 16-month conflict.
The mediator has supported the Russian-backed idea of Iran joining international talks on the crisis and has been careful not to openly back any direct call for Assad to go.
But Annan has also acknowledged that most in the armed opposition would refuse to serve on the same government as Assad or any other member of his inner circle.
Annan met Assad in Damascus on July 9 for what he described as "constructive" talks focused on a new political approach to ending fighting that observers believe has claimed more than 17,000 lives.
But after the latest mass killing in a Syrian village blamed on the army, Annan condemned "a violation of the Syrian government's obligations and commitment to cease the use of heavy weapons in population centres".
The Security Council will be the scene of a new diplomatic standoff in the coming days as Russia wrestles with Western powers over the extension of a three-month mandate of a Syrian observer mission that expires on July 20.
Russia has proposed a resolution extending the UN mission for another three months without any threat of sanctions against Assad should violence continue.
A counter-proposal by Western powers demands economic sanctions against his regime should he fail to pull tanks and troops out of villages and otherwise refuse to comply with the Annan's proposals.
Russia has threatened to veto the Western-backed measure in its current form.