But Olli Rehn , enlargement commissioner for the European Union , has said talks on an association with Serbia will be cut off on April 5 if Belgrade has not handed over Mr. Mladic or Mr. Karadzic by then .
Serbia /location/location/contains Belgrade
Serbia /location/country/capital Belgrade
CC NNP NNP , NN NN IN DT NNP NNP , VBZ VBN NNS IN DT NN IN NNP MD VB VBN RP IN NNP CD IN NNP VBZ RB VBN IN NNP NNP CC NNP NNP IN RB .