BELGRADE, Serbia (AP) - Serbia's nationalists and Socialists from late strongman Slobodan Milosevic's party said Friday they are close to forming a coalition government that would sideline pro-Western parties' declaration of election victory.

The parties said they had agreed late Thursday on a general set of principles for a new "national" government. More meetings will be held Friday to work out the details of a possible agreement, ultranationalist Gordana Pop Lazic said.

A deal between the far-right Radical Party, Prime Minister Vojislav Kostunica's Popular Coalition and Milosevic's Socialists would allow the nationalists to return to power for the first time since Milosevic was ousted in 2000.

They have teamed up to challenge pro-Western President Boris Tadic's coalition, which won the most votes in last Sunday's general elections - but not enough to govern alone.

Tadic has criticized the nationalists' attempts to form a government, and pledged to do all in his power to prevent it. He also has asked the Socialists to join his government.

At stake are Tadic's plans to bring Serbia closer to the European Union after years of international isolation under Milosevic.

The nationalists, however, want to halt Serbia's integration into the EU because more than half of the bloc's member states have recognized Kosovo, the ex-Serbian province Serbs cherish as their medieval heartland. Predominantly ethnic Albanian Kosovo declared independence from Serbia in February.

The nationalists said they had agreed with the Socialists on governing principles - including pro-European integration - but only with Kosovo as part of Serbia. Other priorities would include fighting crime and corruption and developing the economy, the party said in a statement.

Tadic's For a European Serbia coalition is backed by the pro-Western Liberal Party and ethnic Hungarians lawmakers.

The Liberals said Friday that if the nationalists form the government, the pro-Western camp should form a so-called "shadow" Cabinet.