Image copyright AP Image caption An army assault in the final days of the war killed thousands of civilians, it is claimed

The UN should delay releasing a report into atrocities in Sri Lanka's civil war, the new foreign minister has said.

Mangala Samaraweera said Sri Lanka needed time to set up mechanisms to deal with any recommendations in the report, due for release on 25 March.

The UN rights commissioner's probe is expected to document war crimes by the Tamil Tigers and government forces.

Tamil rebels fought for 26 years for a separate homeland, but were crushed by the army in a massive assault in 2009.

Both sides in the conflict have been accused of killing civilians.

An earlier UN report estimated that as many as 40,000 civilians were killed in the final phase alone, mostly by government shelling.

The UN launched its probe last April, saying there had been "an absence of a credible national process with tangible results".

Former President Mahinda Rajapaksa refused to grant visas to the UN investigators, and said only Sri Lankans could conduct such an inquiry.

But Mr Rajapaksa was defeated in a general election last month, and the new government has promised to co-operate with the UN.

"Unlike the previous government, we are not in a state of denial, saying that such violations have not happened," Mr Samaraweera told the Carnegie Endowment for International Peace in Washington.

"We believe such violations have happened. We are ready to ensure that those who have violated human rights in Sri Lanka will be brought to justice through such a mechanism."

The foreign minister is due to meet US Secretary of State John Kerry later, and UN Secretary General Ban Ki-moon on Friday.

He said delaying the report's release until August should give enough time for internal mechanisms to be established.

UN officials said the timetable for the report's release had not been changed.