UN Secretary General Ban Ki-moon dismissed on Tuesday objections by Sri Lanka to his plan to establish a panel to look into possible human rights abuses there and said he would set it up without delay.

Ban told a news conference he was within his rights to appoint the commission of experts to probe possible violations during Sri Lanka's civil war despite a complaint from President Mahinda Rajapaksa this month that the move was unwarranted.

The UN chief also rejected as based on a "misunderstanding" a letter from non-aligned countries at the United Nations charging that he was exceeding his authority.

Ban said the appointment of the UN panel accorded with a joint statement with Sri Lanka issued after he visited Sri Lanka just after the end of the war last May.

"The panel I am establishing will advise me on the standards, benchmarks and parameters based on international experience that must guide any accountability process such as the one mentioned in the joint statement," he said.

"I am convinced that it is well within my power as the secretary-general of the United Nations to ask such a body to furnish me with advice of this nature," he said, adding that the group would report to him directly. "This does not in any way infringe on the sovereignty of Sri Lanka."

A statement issued by President Mahinda Rajapaksa's office on March 6 said the panel would be perceived as interference with the campaign for an April 8 general election and "would compel Sri Lanka to take necessary and appropriate action in that regard."

Ban said that despite the Sri Lankan objection and the non-aligned countries' letter there would be "no delay" in the establishment of the panel. He gave no further details of when it would be set up or who would serve on it.

The Sri Lankan government has denied charges of deliberately targeting civilians and other human rights breaches during the conflict with the Tigers.

Ban has come under pressure from critics who said that the timing of his visit, days after the end of the fighting, appeared to endorse the government's victory. (Reuters)