COLOMBO, Sri Lanka - UN chief Ban Ki-moon appealed to a triumphant Sri Lanka on Friday to seize its moment of victory over the Tamil Tiger rebels to resolve long-standing grievances of the Tamil minority. The world body head also said he would seek permission for more international aid to enter camps where about 280,000 desperate war refugees are sheltered.

The UN secretary-general was due to arrive late Friday for a 24-hour visit. Ban planned to fly by helicopter over the devastated war zone in the north, where the Sri Lankan military has crushed a separatist insurgency that had led to a quarter-century of warfare and suicide attacks.

"This is going to be a defining trip, a very crucial trip for the future of Sri Lanka and peace and stability in the region," Ban told reporters traveling with him on a 12-hour flight from Frankfurt.

Ban's chief of staff, Vijay Nambiar, said Ban will discuss the reconciliation process the government should begin with the Tamils, who are 18 percent of the population and who complain of systematic discrimination and harassment by the Sinhalese majority.

"The process of national reconciliation, we feel, must be all-inclusive so that it can fully address the legitimate aspirations of the Tamils as well as other minorities," Nambiar said. "It is important that victory becomes a victory for all Sri Lankans."

Ban will be the first major international figure to visit Sri Lanka since President Mahinda Rajapaksa declared victory over the rebels earlier this week. That could put Ban in a delicate position between offering assistance to a war-torn nation and appearing to be part of Rajapaksa's victory dance.

Senior UN officials, speaking on condition of anonymity because of the sensitivity of the matter, acknowledged that Ban runs that risk, but expressed confidence he can avoid being manipulated.

"Why shouldn't the secretary-general of the United Nations be there trying to make things better?" said B. Lynn Pascoe, the UN's top political official.

Ban was among many world leaders who had called on the government to halt its offensive so that tens of thousands of Tamil civilians could escape from a murderous crossfire. Those calls were ignored.

At a festive victory rally Friday, Rajapaksa referred to suggestions that he and his leadership should be investigated for war crimes.

"They wanted to take (us) to international criminal courts. Some are trying to do this even now," he told a crowd of many thousands. "But I am not afraid of walking up to any gallows, having defeated the world's worst terrorists, and I know that I have the confidence and the strength of my people."

Releasing casualty figures for the first time, Defense Secretary Gotabhaya Rajapaksa said a total of 6,260 soldiers, sailors and policemen were killed in the latest round of fighting that began in 2006 after a four-year-long cease-fire crumbled. Nearly 30,000 were wounded.

Military spokesman Brig. Udaya Nanayakkara said 22,000 rebel fighters also died in that period, although it was not clear how the figure was calculated. The International Committee of the Red Cross has said it has visited and registered 1,800 rebels who surrendered to the army.

The U.N. says at least 7,000 civilians were killed in the final offensive, and between 80,000 and 100,000 people were killed since the war began in 1983.

The body of rebel leader Velupillai Prabhakaran was cremated and his ashes dispersed "into the air," Nanayakkara said.

Prabhakaran was killed in the final battle after the army had squeezed the remnants of the rebel force into a narrow strip alongside a lagoon. But the circumstances of his death were unclear.

En route to Colombo, Ban said he considered his mission "urgent," and that his main task was to help the estimated 280,000 people displaced in the recent months of fighting who are now housed in government-run camps.

Aid agencies have complained the government was restricting access to the camp, allowing in only essential supplies of food and water.

Epidemics of chicken pox and skin diseases were sweeping through the camp and hepatitis was a growing problem because of poor sanitation, the Oxfam aid agency said.

Most vehicles have been prevented from entering the camps. The military says it is concerned that Tamil rebels may be hiding among the refugees and try to escape if there were a heavy flow of traffic in and out.

Ban said his most pressing task is "insuring the unimpeded access of United Nations agencies and humanitarian workers" to camps.

"I'm going to mobilize all humanitarian agencies of the United Nations and I'm going to appeal to the international community to help," he said.

Just before he departed Ban said he spoke with British Prime Minister Gordon Brown, U.S. Secretary of State Hillary Rodham Clinton and French Foreign Minister Bernard Kouchner, gaining their endorsement of the trip and pledges to offer whatever humanitarian aid they could.

Meanwhile, the International Committee of the Red Cross said it had been allowed to speak Thursday with three government doctors who ran an overwhelmed makeshift hospital in the war zone and were detained by the government on accusations they gave false information to the media about civilian casualties.

International human rights groups have demanded the government release the doctors and give them access to legal counsel.

"The ICRC saw them and spoke in private to them," said Red Cross spokeswoman Sarasi Wijeratne. She gave no details of their conditions.