Serbian President Boris Tadic has announced his resignation, clearing the way for an early presidential election.
The move -- coming 10 months before Tadic's term was formally due to expire at the end of the year -- sets the stage for joint parliamentary and presidential elections in May.
Serbia is to hold parliamentary and local elections on May 6.
Tadic said he will seek reelection in the poll. He is expected to submit his resignation to the speaker of parliament on April 5.
The move is being seen as an effort to boost the chances of Tadic's Democratic Party in the parliamentary elections.
Analysts say the party is seeking electoral gains based on Tadic's personal popularity among voters.
The Democratic Party has seen its approval ratings slip in recent polls, with the opposition nationalist Serbian Progressive Party emerging in first place. The party's leader, Tomislav Nikolic, is challenging Tadic for the presidency.
Tadic said on April 4 that he expected the election to be "tough."
'Deciding Which Path Serbia Will Take'
Tadic's government has been blamed for Serbia's economic and social problems.
But it got a welcome boost in March when Serbia became an official candidate for membership of the European Union.
Serbia was granted candidate status after the arrest and extradition last year of Bosnian Serb wartime leader and genocide suspect Ratko Mladic.
Tadic said that in the upcoming election, voters will have "the opportunity to decide which path Serbia will take." He said he was offering "a road of European integration."
Future progress on the way to EU membership will depend on improved relations between Belgrade and Kosovo, whose ethnic Albanian majority leadership declared independence in 2008.
Belgrade refuses to recognize Kosovo's independence, insisting the territory remains Serbian.
Following his resignation, Tadic's official duties will be carried out in the interim by the parliamentary speaker, socialist Slavica Djukic-Dejanovic, who is also due to formally announce the presidential election date.
The president of Serbia is elected to a five-year term.
Tadic has effectively already served two terms as president. He is eligible to run for a third term because he was first elected to the post in 2004, when Serbia was part of a union state with Montenegro.
That same year, Tadic became leader of the Democratic Party, succeeding Serbia's assassinated Prime Minister Zoran Djindjic.
With reporting by Reuters, AP, and dpa