Russian President Vladimir Putin met in Moscow on March 27 with Serbian Prime Minister Aleksandar Vucic, with both men lauding the close relations between the two countries.
Noting that Serbia is conducting a presidential election campaign, Putin said Russia is "wishing success to the incumbent authorities."
Vucic is the favorite in the April 2 vote after President Tomislav Nikolic decided not to seek a second term.
Earlier in the day, Putin's spokesman, Dmitry Peskov, said "there can be no talk that the Kremlin interfered in any electoral processes."
Vucic also confirmed that Russia will provide "as a gift" six MiG-29 fighter jets, which will arrive in Serbia "within several days or several weeks."
Vucic said the planes would enter military service by the end of the year following refurbishing.
Russia will also provide 30 T-72 tanks and 30 BRDM-2 patrol combat vehicles to Serbia for free.
Vucic, a former nationalist, has remade himself as a pro-European Union reformer while seeking to maintain good relations with traditional ally Russia as well.