Russia said Sunday that removing Syrian President Bashar al-Assad from power was not part of past international agreements on the crisis and was impossible to implement, AFP reports.
"This is a precondition that is not contained in the Geneva communique (agreed by world powers in June) and which is impossible to implement because it does not depend on anyone," news agencies quoted Foreign Minister Sergei Lavrov as saying.
Lavrov conceded that a defiant speech Assad delivered on January 6 calling for peace in Syria on his own terms probably did not go far enough and would not appease the armed opposition.
But he also urged Assad's enemies to come out with a counterproposal that could get serious peace talks started between the two sides for the first time.
"President Assad has forwarded initiatives aimed at inviting all in the opposition to dialogue. Yes, this initiative probably does not go far enough," said Lavrov.
"They will probably not look serious to some. But these are offers. And if I were in the opposition's place, I would present my counter-ideas about establishing dialogue."
Russia on Saturday reiterated its support for a transition plan that was agreed in Geneva on June 30 but never implemented because of the fighting.
The accord is now being heavily promoted by Lakhdar Brahimi, the UN-Arab League envoy for the 21-month crisis in Syria.
The Geneva deal calls for power to be handed to an interim government but offers no clear guidance about Assad's future role.
But Moscow is deeply worried that Brahimi is getting ready to back a firmer version of the Geneva pact that specifically precludes the possibility of Assad or his closest advisers serving on the transition team.
Russia argues that only the Syrian people themselves can oust Assad through either elections or some form of negotiated settlement.
It also accuses Washington of using its armed forces more freely to depose unfriendly regimes -- a practice that Russia says breaches international law.
Western powers and Arab states -- as well as the armed opposition -- counter that the Geneva plan promoted by Brahimi can only work if Assad steps down.
Russia's firm stance comes despite a series of recent assurances by President Vladimir Putin that Moscow was not interested in propping up Assad.
Putin even noted in his annual press conference last month that he understood Syrians' impatience for change after more than 40 years of rule by the Assad family.
But Lavrov -- enjoying unparallelled access to the regime -- argued that a broader international call on Assad to step down would have no effect on the Syrian leader and would only incite further unrest.
"If you make the Syrian president's ouster the main precondition, then -- and I have said this before -- the price for this approach is new fatalities," said Lavrov.
"And those who support such an approach must bear the responsibility for it."