Sri Lanka will not cooperate with a United Nations inquiry into alleged war crimes by government forces and separatist Tamil Tiger rebels in the final phase of their 26-year war, its foreign minister said on Monday, Reuters reported.

The UN, through a United States-led resolution, last month set an international inquiry into the alleged war crimes and human rights abuses after the island nation's government had failed to investigate them properly.

Sri Lankan government has rejected the allegations.

External Affairs Minister G.L. Peiris said the government had not accepted the UN investigations due to concerns over its legality, fairness, and some conflict of interest issues.

"Where the government is required to do anything to support the investigation or to participate in it, the government will not do that," Peiris told a Foreign Correspondents Association (FCA) forum on Monday. "Nobody can come here without the cooperation of the Sri Lankan government."

However, the government will not prevent anybody from giving evidence to any such investigation as there could be various views from different people, he said.

It is still not clear how the UN would conduct its probe, Peiris said.

"They will have to tell us what they want to do. But the clear policy decision had been taken that we do not associate ourself with the inquiry and we do not submit to the jurisdiction of the investigating committee," he said.