Burma's military government has given permission for a U.S. military plane to deliver emergency aid to survivors of last week's cyclone that killed more than 22,000 people.

A spokesman for the U.S. embassy in Bangkok announced the development Thursday. Details of when the relief mission will occur have not been revealed.

A washed away house in Dedaye, some 48 kilometers south of Rangoon, 07 May 2008

Meanwhile, the United Nations says it is still waiting on clearance from Burma for its planes to deliver aid. Officials with the U.N.'s World Food Program says three planes filled with tons of supplies are waiting to take off from Thailand, Bangladesh and Dubai.

A fourth plane -- a Thai commercial cargo plane -- is supposed to arrive today carrying a large supply of high-energy biscuits. A small U.N. disaster team has also been cleared to enter the country today.

International leaders have been urging Burmese rulers to allow relief workers and supplies into the country to assist one million people left homeless by Cyclone Nargis.

Officials say another 42,000 listed as missing. The top U.S. diplomat in Burma, Charges d'Affaires Shari Villarosa, warned Wednesday that the death toll from Nargis may reach 100,000.

The ruling military junta has welcomed international relief efforts, but has not eased visa and customs procedures. The U.S. and other Western countries have been critical of Burma's government, which has in turn accused the U.S. of trying to subvert its rule.

France has suggested the U.N. invoke its "responsibility to protect" clause and deliver aid directly to Burma without the ruling military's approval.

A spokesman for the U.N.'s humanitarian agency says about 5,000 square kilometers of the low-lying Irrawaddy River delta region were under water.