Russian Foreign Minister Sergei Lavrov arrived in Damascus on Monday for his first visit in around eight years, state television said.
Lavrov joins Russian Deputy Prime Minister Yury Borisov, who arrived on Sunday in Damascus.
Heading a large delegation, the two will conduct political, economic and military talks with high-ranking Assad regime officials, the television broadcast added.
Lavrov and his Syrian counterpart, Walid al-Moallem, are expected to stage a press conference at 4 pm (1300 GMT).
This is Lavrov's first visit to the Syrian capital since 2012, Syrian television reported.
President Vladimir Putin made his first trip to Damascus in Syria's nine-year-old war in January this year.
The Russian leader also visited Syria in December 2017 but had not been to the capital, only stopping at the Russian base of Hmeimim on the Mediterranean coast.
Russia has been a key ally of the Damascus regime throughout the Syrian conflict that erupted in 2011 with the repression of anti-government protests.
Moscow's military intervention in 2015 helped turn the tide of the war, with Russian air power allowing Syrian government forces to win back large parts of the country.
The conflict has ravaged the Syria economy, killed more than 380,000 people and pushed millions to flee their homes.
