Mr Annan said: "It is indeed tragic that diplomacy has failed but there are times when the use of force may be legitimate in the pursuit of peace.

"But as secretary-general I have many times pointed out, not just in relation to Kosovo, that under the Charter the Security Council has primary responsibility for maintaining international peace and security - and this is explicitly acknowledged in the North Atlantic Treaty.

"Therefore, the council should be involved in any decision to resort to the use of force.''

He spoke after Nato unleashed a first wave of bombs on Yugoslavia, and began by saying he was speaking "at a grave moment for the international community".

Grave moment

Britain, the US and their allies maintain they have authority to launch Nato strikes based on previous Security Council resolutions demanding a peaceful settlement in Kosovo.

Those resolutions were enacted under chapter seven of the UN Charter, and the article allows for resolutions to be militarily enforced.