The European Union's expansion commissioner is warning Serbia and Montenegro that the country risks cancellation of its EU association talks unless it surrenders leading fugitive war crimes suspects.

Olli Rehn made his comments in Brussels after talks with the chief prosecutor of the United Nations war crimes tribunal, Carla del Ponte.

The prosecutor repeated her belief that war crimes suspect General Ratko Mladic, the former top Serb military commander in Bosnia-Herzegovina, is hiding in Serbia under the protection of the republic's military. She stressed her determination to put the general on trial by July for his role in the Srebrenica massacre.

Serb forces killed about 8,000 Muslim men and boys after capturing Srebrenica in 1995 in what international human rights groups call the worst massacre in Europe since World War II.

Some information for this report was provided by AFP, AP and Reuters.