After his meeting with Serbian President Boris Tadic and other Serbian officials in Belgrade on Thursday, Rehn told the press that the EC had adopted a revised mandate for negotiations with Serbia which removed technical obstacles to the resumption of the talks.
The talks were suspended two months ago following Belgrade's failure to locate and arrest Mladic, who is wanted by the International Criminal Tribunal for the former Yugoslavia (ICTY) on genocide charges.
"Full cooperation with the ICTY, which needs to lead to the arrest and transfer of Ratko Mladic, remains the necessary condition to resume the talks for the SAA agreement," Rehn was quoted by Reuters news agency as saying after meeting Tadic.
Rehn applauded Belgrade's intention to draw up an action plan for the improvement of cooperation with the ICTY, but stressed that the results of the action must be more important than preparations for the plan.
President Tadic told reporters that "there is no alternative to Serbia's EU full membership", adding that EU membership was one of the priorities of the Serbian government.