BELGIAN FOREIGN MINISTER KAREL DE GUCHT WARNED SERBIA THAT FAILURE TO RESPONSE TO SUNDAY'S EUROPEAN UNION DEADLINE TO EXTRADITE WAR CRIMES FUGITIVE GEN. RATKO MLADIC TO THE U.N. WAR CRIMES TRIBUNAL WILL RISK STALLING CLOSER TIES WITH THE REST OF EUROPE. DE GUCHT, CURRENT CHAIRMAN OF THE ORGANIZATION FOR SECURITY AND COOPERATION IN EUROPE, SAID BELGRADE HAD TO DO EVERYTHING IT COULD TO FIND AND HAND OVER MLADIC.