Three weeks after the cyclone that devastated Burma, Ban Ki Moon, the United Nations Secretary-General, finally arrived for talks with the generals who had refused to take his calls, answer his messages or respond to his earlier urgent pleas to admit international aid and expertise. Even as he arrived, hundreds more died in the Irrawaddy delta from the junta's criminal neglect of their need. And as if to mock his cautious, low-key attempt to open the doors to foreign help, Burma announced that it would not accept any of the food, water purifying kits or helicopters that have been waiting on board four US navy ships off the Burmese coast for ten days or the 1,000 tonnes of emergency supplies on a French ship. There could be no more cynical proof of the generals' callous indifference to Burma's suffering and rising death toll.

Few have hopes that Mr Ban will achieve much. His own indifferent record in office has not given the UN the muscular authority it ought to command. In Burma he is further hampered by the junta's suspicion, exacerbated since the world's condemnation last year of its bloody suppression of the protests, that the UN is an instrument of Western policy and is part of a US-led conspiracy to topple the generals. Mr Ban was given a brief official tour yesterday of the disaster area. But any hope this might have raised that the Government was ready to let the world see the real plight of the 2.5 million people struggling to survive was quickly undercut by its announcement that the relief operation was over and that the focus had shifted to reconstruction.

Mr Ban needs to use this rare opportunity to speak out. He needs to tell the generals that their insistence on holding a second round of the referendum to entrench their power is a charade, made all the more obscene by the corpses still decomposing in the fields and villages. He needs to heed the warnings by Burmese exiles and those few monks brave enough to speak out that the junta is going through the motions of co-operation but is set instead on ignoring all outside pressure, just as it has ignored all UN-sponsored attempts to begin a political dialogue inside Burma. And he needs to warn them that denying lifesaving aid to thousands of victims is a grotesque and indictable crime against humanity.

The dilemma for relief organisations is whether the very limited amount of help now getting through justifies continued patience. The danger always is that aid agencies - realistic in their assessment that in every disaster in every country a proportion of aid is stolen or diverted - will turn a blind eye to the bureaucracy, delay and political obstruction frustrating their work in Burma. Several still argue that using official channels, however meagre the result, is better than defying the junta with air drops. But if, as we report today, even the aid being allowed in through Asian channels is being diverted to profiteers and cronies of the junta, the moral balance changes. The suffering Burmese might well be better off if the outside world ignored xenophobic restrictions and risked open confrontation. Mr Ban needs to make this plain in his talks today with General Than Shwe, the junta leader. Persuasion will not move this paranoid leadership. Only the threat that an anguished and angry world is preparing for action may bring results. Otherwise, that action must begin now.