The United Nations war crimes tribunal set up in the wake of the Balkan conflicts in the 1990s will need more time to complete its work after originally being scheduled to wind down at the end of 2010, UN Secretary-General Ban Ki-moon said on March 16.

Speaking at UN Headquarters in New York, Ban said that "there is some broad agreement now that the ICTY [International Criminal Tribunal for the former Yugoslavia] may need at least a few more years, to 2013 or so," before it can finish its work, the UN News Service reported.

Based in The Hague, the ICTY was tasked by the UN Security Council with trying the worst war crimes and other breaches of international humanitarian law committed during the various conflicts in the former Yugoslavia in the 1990s.

Under a completion strategy struck with the Council, it was scheduled to begin downsizing this year, in line with its nature as a temporary institution.

The tribunal has concluded proceedings against more than 120 accused since it began work and trials or appeals are pending or continuing in several dozen cases.

Two leading suspects remain at large, Bosnian Serb military chief Ratko Mladic and ethnic Serb politician Goran Hadžic, with both facing a lengthy series of charges.

"If and when these two fugitives are arrested, then we will have to discuss again how we can adjust, or we can leave it other mechanisms – this was discussed already between the ICTY and the Security Council," Ban said.