Washington on Thursday resumed aid to Serbia and Montenegro frozen earlier this year and said it was confident that top war crimes fugitive Gen. Ratko Mladic would not be on the run much longer. Mladic was the commander of the Bosnian Serb army during the 1992-95 war and is wanted by the United Nations war crimes tribunal in The Hague to face charges of genocide. Belgrade's failure to capture him has long hampered its ties with the West. "My strong impression from my discussions in Belgrade is that the government is working very seriously to find General Mladic and there will be a sincere attempt to capture him or to have him voluntarily surrender and to send him to The Hague," Under-Secretary of State Nicholas Burns told reporters. "We are confident that his days in relative freedom are numbered," Burns told reporters after talks with the Serbian president and prime minister, according to Reuters. U.S. aid was frozen in January to express Washington's dissatisfaction with Belgrade's level of cooperation with the war crimes tribunal. Burns said aid was being restored immediately to reward the government of Prime Minister Vojislav Kostunica for success in convincing a dozen war crimes suspects -- mainly former generals -- to surrender to The Hague since January. "It is our very strong hope that Serbia will take the final step and send General Mladic to The Hague," Burns said. Once he is in custody "I think you will find that Europe and my own country will look for ways to build a much better and closer relationship" with Serbia-Montenegro and its governments. --More 1555 Local Time 1255 GMT