NAIROBI, Kenya (AP) _ Responding to lingering questions about U.N. inaction during the 1994 Rwandan genocide, U.N. Secretary-General Kofi Annan said Monday he lacked the military might and political backing to stop the slaughter of more than 500,000 people.

``If I had had one reinforced brigade, that is firepower and men _ well-trained and well-equipped _ I could have saved hundreds of thousands of lives,'' he said.

U.N. members refused to provide the support needed by Canadian Gen. Romeo Dallaire, commander of U.N. forces in Rwanda, Annan said during an eight-nation African tour that includes a stop in the Central African country.

The question of why more wasn't done to stop the killing in Rwanda has gained new attention with a trip by President Clinton to the region and the four-year anniversary of the genocide. Clinton apologized for not intervening, and promised there would not be a repeat of that passivity.

``The failure to prevent the 1994 genocide was local, national, international, including member-states with important capacity,'' Annan said Monday. ``The will to provide, the will to act, was not there.''

``But the crucial issue today is not how to apportion blame with the benefit of hindsight, but rather we should be asking how to ensure that such a tragedy will never happen again.''

Annan downplayed a story in May 11 edition of the The New Yorker magazine that faulted him for failing to be aggressive enough in responding to a warning about plans for mass killings in Rwanda.

The senior U.N. military officer on the ground in Rwanda, Dallaire, told Annan he was preparing a raid on a weapons armory within 36 hours, but Annan overruled him, citing restrictions in the Security Council mandate authorizing the peacekeeping force.

``It's an old story and the issue has been around for quite awhile and lots of explanations have been given,'' Annan said Monday.

Filip Reyntjens, a Belgian who published an authoritative chronology of the genocide in February 1996, said Annan should order the United Nations to investigate its own failings in Rwanda.

``If you say that everyone is responsible, then what he's saying is that no one is responsible. He should be more specific about it, his own responsibility, and the U.N.'s responsibility. The United Nations as an institution has failed.''

The genocide began April 6, 1994, and by the time it was over three months later, Hutu extremists had killed more than 500,000 people, mostly Tutsis.

Annan headed U.N. peacekeeping operations on Jan. 11, 1994, when Dallaire warned the world body that Hutus were planning the slaughter. In a fax sent to U.N. headquarters in New York, Dallaire quoted a senior Rwandan security official as saying he had been ordered to register all Tutsis in Kigali for the purpose, he suspected, of ``their extermination.''

On Jan. 12, 1994, U.N. special envoy Jacques Booh-Booh of Cameroon was told to give the American, French and Belgian ambassadors to Rwanda a full accounting of the contents of the report. Booh-Booh did so.

On Feb. 10, U.N. Undersecretary-General Chinmaya Gharekhan briefed the 15-member Security Council, which authorizes and oversees peacekeeping operations, about the deteriorating situation in Rwanda.

The United States and France are permanent members of the Security Council. Along with Belgium, those countries had a significant interest in the region at the time of the Rwandan crisis.

None of the three countries was willing to intervene to prevent the genocide _ a lack of support that prevented any expansion in the mandate of the peacekeeping force. The United Nations cannot act in such matters without Security Council's approval.

``Each country has a right to decide when to participate in a peacekeeping operations and when to withdraw its troops,'' said Annan, who became U.N. secretary-general in October 1996, replacing Boutros Boutros-Ghali.

In 1993, 18 U.S. soldiers were killed in Somalia during a U.N. peacekeeping mission, leading to the United States to begin withdrawing its troops deployed there. The incident, just four months before Dallaire's fax, left the United States firmly opposed to military intervention.

After 10 Belgian peacekeepers were killed in Rwanda on April 7, 1994, Belgian withdrew its entire contingent from the country, although the genocide was ongoing. Other countries followed suit, and of 2,500 peacekeepers just 270 remained.

A French parliamentary panel is investigating that country's role in the genocide following reports it secretly armed the Hutus during the bloodshed.