Five helicopters working on cyclone relief for the United Nations arrived Saturday in Burma's former capital of Rangoon.

They join another U.N. helicopter that arrived Monday to carry supplies to survivors of Cyclone Nargis which killed more than 78,000 people and left 56,000 missing.

The U.N. says only half of the country's estimated two million cyclone victims have received food, water, shelter or health care from aid agencies.

The U.N.'s World Food Program has another four helicopters waiting in Thailand to join the relief effort.

Burma's ruling junta blocked many direct relief efforts by foreign organizations and governments to the hard-hit Irrawaddy River delta following the May third cyclone which left 56 thousand missing.

The U.S. has offered Burma 22 helicopters and says that it can get aid to a majority of hungry and homeless survivors in a matter of days.

U.S. military ships carrying relief supplies and helicopters have moved away from the Burmese coast, but U.S. military officials say they can return to help with relief if asked.

Some information for this report provided by AP, AFP and Reuters.