Aleksandar Vucic stepped down as president to seek the prime minister's post in an early parliamentary election, following nearly two years of protests in Serbia.
The Serbian head of state intends to run for the post of prime minister in the legislative elections in October.
Serbia's early parliamentary election is unlikely to resolve the political crisis or ease the pressure facing President Aleksandar Vucic, according to analysts.
Aleksandar Vucic stepped down as Serbia's president and will lead his ruling party into a snap parliamentary election.
Vucic intends to run again in snap elections despite months of student-led demonstrations challenging his rule.
The Russian and Serbian presidents held a call on energy, transport and healthcare cooperation as a key gas supply arrangement nears expiry.
Serbian President Aleksandar Vucic congratulated Russian President Vladimir Putin on the outcome of Russia's State Duma elections, according to TASS.
Russian President Vladimir Putin spoke by phone with Serbian President Aleksandar Vucic in what the Kremlin described as a warm and friendly atmosphere.
The meeting is expected during the UN's high-level general debate in New York later this month, according to TASS.
Aleksandar Vucic said Serbia would be willing to host negotiations on the Ukraine conflict but suggested an Arab country was more likely to be chosen.