AP photo/Ho, U.S. Marine Corps, Sgt Andres Alcaraz
A soldier from Myanmar and a U.S. airman unload food packages at Yangon airport Monday. It was the first U.S. aid to be delivered following Cyclone Nargis.

UNITED NATIONS — As the authorities in Myanmar raised the cyclone death toll to nearly 32,000 and admitted one U.S. military aircraft, U.N. Secretary-General Ban Ki-moon pressed the junta to let international assistance and aid workers into the country without hindrance and expressed "deep concern and immense frustration" with what he called "the unacceptably slow response to this grave humanitarian crisis."

In unusually blunt language for a U.N. leader, he said, "This is not about politics; it is about saving people's lives. There is absolutely no more time to lose."

The sharp comments from Ban came on a day when the authorities in Myanmar allowed a U.S. military aircraft to land with relief supplies Monday, crossing one barrier that has hindered the delivery of large-scale aid to more than a million victims of the May 3 cyclone. Meantime, state television has put the death toll at 31,938, with 29,770 people missing.

The U.S. flight was the most public example of what aid groups said was a slight easing of restrictions over the last day, although not nearly enough to provide for what they said was a desperate — and increasing — need.

Ban said that he had been trying for four days without success to reach the country's senior general, Than Swe, and had sent a second letter to him Monday alerting him to the United Nations' efforts to provide help and its need for "greater access and freedom of movement."

U.N. officials said that the distribution of most deliveries of international relief supplies were still being blocked to the most badly affected parts of the country. They said help was reaching fewer than one-third of those in need.

By their stubbornness in refusing to allow the rapid distribution of relief supplies, the generals who rule Myanmar are turning the cyclone that struck more than a week ago from a devastating natural disaster into a man-made disaster of huge proportions.

As the disaster grows and pressure from the outside world intensifies, the junta faces a dilemma.

If it opens its doors to large numbers of foreigners, it may never be able to seal the country again against the outside influences and interference it dreads.

By keeping foreign assistance out, though, the generals must be ready to accept the deaths of hundreds of thousands more people, according to foreign relief officials.