Russian President Vladimir Putin congratulated Serbia's leader Aleksandar Vucic on his re-election victory and said he hoped to build on their "strategic partnership", the Kremlin said.
"I expect that your work as head of state will continue to contribute to the strengthening of the strategic partnership that exists between our countries," Mr Putin said in his telegram to Mr Vucic, according to the Kremlin statement.
"This undoubtedly meets the interests of the fraternal peoples of Russia and Serbia."
The Kremlin praised the Serbian leader's "convincing" victory, adding that Mr Putin hailed his "independent" foreign policies.
The 69-year-old Russian leader has been increasingly isolated internationally after he sent troops to pro-Western Ukraine on February 24.
Mr Vucic has been one of his rare allies in Europe.
He has carefully managed Serbia's response to Russia's military campaign in Ukraine by officially condemning Russia at the United Nations but stopping short of sanctioning Moscow at home, where many Serbs hold a favourable view of the Kremlin.
Mr Vucic claimed a landslide victory in general elections yesterday, paving the way for another term as president and extending his decade-long rule in the Balkan nation.