The Foreign Ministry also said in a statement that agreement on a ceasefire and the withdrawal of government troops and rebel forces from cities would create a "favorable atmosphere" for a political transition.
Although the ministry welcomed the convening of the talks as a positive move, the statement pointed to no rapprochement with Western powers over plans for a political transition in Syria.
The ministry released its statement shortly before a dinner in St Petersburg at which U.S. Secretary of State Hillary Clinton was expected to try to persuade Russian Foreign Minister Sergei Lavrov that Moscow should agree to Syrian President Bashar al-Assad’s departure.
Regretting Saudi Arabia, Iran, Jordan and Lebanon would not take part on the talks on Saturday with foreign ministers of the five permanent members of the U.N. Security Council, it said: "The Russian proposal on this has met unsurmountable objections from the U.S. side, especially on the part concerning Iran."
Turkey, Kuwait, Qatar, U.N. Secretary-General Ban Ki-moon and Arab League chief Nabil Elaraby will also attend.
International mediator Kofi Annan will seek backing for a proposal that does not explicitly stipulate that Assad must step down, but does call for a unity government that would exclude figures who jeopardise stability.
Diplomats said Russia proposed changes on Thursday to Annan’s plan for a national unity government, despite initially supporting it, but the United States, Britain and France rejected the amendments.
