BELGRADE, September 11, 2008 (AFP) - President Boris Tadic said Thursday that Serbia is 'determined' to arrest Bosnian Serb genocide suspect Ratko Mladic as the UN chief war crimes prosecutor leaves Belgrade optimistic about the case.

Tadic told the prosecutor, Serge Brammertz, that the 'new authorities in Serbia showed their firm determination' already by arresting Mladic's wartime political leader, Radovan Karadzic, said a statement from his office.

Serbia was 'fully aware of its international and domestic legal obligations to (ensure) that remaining fugitives must end up in the Hague,' where the UN war crimes tribunal is based, it added.

Brammertz was given the same message from Serbian Prime Minister Mirko Cvetkovic, whose government ordered the arrest of Karadzic in late July, around two weeks after it took office.

The International Criminal Tribunal for former Yugoslavia (ICTY) prosecutor expressed a 'careful optimism' Wednesday that Serbia would locate and arrest the two remaining suspects, Mladic and a Croatian Serb leader Goran Hadzic.

Brammertz made the statement after meeting his Serbian counterpart Vladimir Vukcevic and a Serbian government 'Action Team' formed to focus on the search for the fugitives.

His meetings on Thursday 'also were held in a positive and constructive atmosphere,' the prosecutor's spokeswoman Olga Kavran told AFP prior to his departure from Belgrade following the two-day visit.

Serbia expects Brammertz to provide a positive evaluation of its cooperation with the ICTY, a key condition set by Brussels for its further integration into the European Union.

Brammertz is expected to brief EU officials in Brussels on the level of cooperation ahead of a meeting of the 27-nation bloc's foreign ministers scheduled for Monday.