A Russian official said in July the Moscow would not deliver fighter planes or other new weapons to Syria while the conflict there remained unresolved.
Russia and China, both permanent Security Council members, have vetoed three Western-backed U.N. draft resolutions condemning Assad’s government for its handling of the uprising that began with peaceful demonstrations in March 2011.
The protests turned into an armed revolt after Assad used force to crush opposition. About 32,000 people have been killed.
Lavrov, who met Lakhdar Brahimi, the international mediator on Syria, in Cairo on Sunday, said the Syrian government and the opposition should be forced to sit down to negotiations. Lavrov was due to meet the Egyptian foreign minister later on Monday.
(Reporting by Shaimaa Fayed; Editing by Edmund Blair and Alistair Lyon)