UN officials criticize Myanmar's response to cyclone

"I'm disappointed by the progress we've seen," Holmes told reporters. He called the situation "profoundly worrying" and emphasized the U.N. was only trying to help Myanmar deal with an "increasingly desperate" situation.

Some diplomats had sharp words for Myanmar's response.

U.S. Ambassador Zalmay Khalilzad told reporters Thursday the U.S. was "outraged by the slowness of the response of the government of Burma to welcome and accept assistance."

"It's clear that the government's ability to deal with the situation, which is catastrophic, is limited," he said. The "government has responsibility to protect its own people, to provide for its people, and since it's not able to you would expect the government to welcome assistance from others."

China cautioned against political rhetoric.

"I think it's more important not to link any issue of Myanmar to politics -not to politicize the issue," China's deputy U.N. ambassador Liu Zhenmin told reporters.