Serbian President Boris Tadic has set May 6 as the date for the country's parliamentary elections.

Mr. Tadic's ruling Democratic Party will face a strong challenge for the 250-seat national assembly from the nationalist Serbian Progressive Party, headed by opposition leader Tomislav Nikolic.

The election comes after European Union leaders made Serbia an official candidate for EU membership earlier this month.

The 27-member bloc says Serbia has made a number of reforms demanded by the EU, including arresting and extraditing war crimes suspects and improving relations with its former province of Kosovo.

Kosovo's 2008 declaration of independence is supported by the United States and a majority of EU countries.