Defense Secretary Gotabaya Rajapaksi, in the first official statement about Sri Lanka forces' casualties, said another 30,000 troops were injured, the BBC reported.
Sri Lanka officially announced an end to the war this week after government troops seized a parcel of land held by the rebels, saying the top Tamil Tiger leaders, including their chief, Velupillai Prabhakaran, were killed in combat.
No official figures for the number of Tamil Tiger rebels killed in the civil war were available, although estimates range between 15,000 to more than 22,000, the British broadcaster said.
U.N. Secretary-General Ban Ki-moon was to arrive in Sri Lanka Friday to discuss the situation with representatives of roughly 275,000 displaced people, the BBC said. Humanitarian aid groups have complained about restricted access to refugee camps.
On Thursday, U.N. envoys met Sri Lankan President Mahinda Rajapaksa and said they were told said most of the displaced Tamils would be resettled within six months.
Ban's envoy, Vijay Nambiar, also in Sri Lanka, said there had to be political reconciliation between the government and the rebels, who fought for decades for an independent state.
"The process of national reconciliation, we feel, must be al-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."