UNITED NATIONS -- Secretary-General Kofi Annan has apologized for the United Nations' role in the 1994 Rwandan genocide and has pledged to use a highly critical report to ensure that another mass slaughter of civilians doesn't occur again.

Annan acknowledged Thursday that the United Nations and its member states failed Rwanda and its people during the 100-day genocide and expressed his "deep remorse" that more wasn't done to stop it."Of all my aims as a secretary-general," Annan said in a statement, "there is none to which I feel more deeply committed than that of enabling the United Nations never again to fail in protecting a civilian population from genocide or mass slaughter."

Annan was responding to an independent investigation he commissioned in March to learn the truth about the U.N. role in the genocide so that the United Nations could learn lessons for the future.

The report found that the fundamental failure of the U.N. was that the organization and its members lacked the political will and resources to prevent the genocide or stop it once it was under way.

In Rwanda, officials said Annan's expression of "deep remorse" was not enough. "Is that how people apologize?" asked Rwandan government spokesman Joseph Bideri.

"As far as the Rwandan people are concerned . . . they were betrayed by the U.N. in their hour of need," Bideri said in the Rwandan capital, Kigali. "Expressing remorse and making a public apology are two different concepts. So we haven't had the apology."

Joseph Mutaboba, Rwanda's U.N. ambassador, called the report "objective."

"Public apology is a first step, and it should be followed by a personal apology" by Annan, Mutaboba told the BBC.

He also ruled out that the report could have negative consequences on the relations between Rwanda and the United Nations.

"We don't see those relations deteriorating because of the report . . . It's up to the U.N. to pick up the pieces," he said.

An estimated 800,000 people, most of them minority Tutsis, were killed in the Hutu-sponsored genocide that began after the April 6, 1994, downing of the Rwandan president's plane.

The report singled out Annan, then chief of the U.N. peacekeeping department, for failing to alert the Security Council of key developments and to recommend the United Nations strengthen the peacekeepers on the ground once the bloodletting began.

Annan's spokesman Fred Eckhard said the U.N. chief planned to use the report -- and a similar analysis of the U.N.'s role in the fall of the U.N.-protected enclave of Srebrenica during the Bosnian war -- to draw specific conclusions for the future.

"He will continue to change policies, retool the Secretariat if necessary," Eckhard said. At a minimum, he plans to change U.N. procedures so that the United Nations organization "is much less likely to be fingered for the kinds of things that this report credibly documents were our failures."

In particular Eckhard said, Annan plans to improve communications with the Human Rights Commission -- a key source of information about on-the-ground developments in countries.

Already the United Nations has changed the way in which it shares information with the Security Council, a shortcoming cited many times in the report. During the genocide, then-Secretary-General Boutros Boutros-Ghali designated one person to brief the council on all topics on its agenda.

Now, experts in each field regularly brief the council -- often requesting to bring issues and developments to the council's attention that the council doesn't necessarily want to hear about, Eckhard said.