Brussels  - The European Union should reward Serbia for the capture of war-crimes indictee Radovan Karadzic by implementing a deal on trade liberalization, the EU's top official said Wednesday during a visit of Serbian President Boris Tadic to Brussels.

And European Commission President Jose Manuel Barroso said that he believed Serbia could become a candidate for EU membership as early as in 2009 if it continues to bring in key reforms.

Describing the July capture of Karadzic as a "milestone" and a "historic moment," Barroso said "I think it should be acknowledged by implementing the trade-related parts" of a broader political deal which the EU and Serbia signed in the spring.

"I believe that if everything goes according to plan and if all the conditions are met, it would be possible to give candidate status to Serbia in 2009," he said.

However, he stressed that the decision lies in the hands of EU member states, and that Serbia would have to continue with political and economic reforms if it wants to move closer to membership.

Tadic welcomed the comments, saying that the implementation of the trade deal was one of three key steps towards his country's main strategic goal of full EU membership.

And he stressed that his government was doing everything in its power to arrest two war-crimes suspects, Ratko Mladic and Goran Hadzic, who are wanted by international prosecutors in the Hague.

"The first day after we find them, we will deliver them," he said.

Since the beginning of the year the EU has been engaged in an intricate diplomatic dance with Serbia, offering Belgrade a series of deals in a successful bid to boost pro-EU voters in crucial presidential and parliamentary elections.

The key move was the decision on April 29 to sign a Stabilization and Association Agreement (SAA, seen as a precursor to candidate status) immediately before parliamentary polls on May 11.

However, under pressure from the Dutch government, the EU decided not to ratify the full deal until Serbia is judged to be cooperating fully with the International Criminal Tribunal for the former Yugoslavia (ICTY) in the Hague.

Dutch officials insist that they will only withdraw their veto once Mladic is arrested and handed to the Hague and ICTY's chief prosecutor, Serge Brammertz, has certified that Belgrade is cooperating fully with his organization.

Brammertz is set to visit Belgrade on September 10 and is expected to brief EU foreign ministers at a formal meeting on September 15. (dpa)