Grounds crew load relief supplies onto a Royal Australian Air Force C-130 Hercules

Torrential rains and flooding are complicating efforts to reach areas hardest hit by the Asian tsunami. As tens of thousands of relief workers battle the elements, the United Nations is appealing for more transport planes to ferry in the massive amounts of aid needed for survivors.  The tsunami death toll is being ranked among the worst natural disasters in modern history.

U.N. emergency relief coordinator Jan Egeland Tuesday reported extraordinary progress in reaching the majority of people affected by the tsunami. At the same time, he spoke of huge obstacles in getting aid to victims, particularly in the remote Aceh region of northern Sumatra.

On day nine of the relief effort, Mr. Egeland said the challenges include building and repairing airstrips to bring in desperately needed supplies. He said the United States, Britain and other countries are being pressed to send more of their largest cargo planes.

Jan Egeland

"On top of my wish list today has been these C-17 aircraft, which are some of the biggest military transport aircraft made  to go in shuttle with heavy, heavy equipment to Banda Aceh, including heavy earthmoving equipment, which should make it possible to make this one-lane air strip into a real airport that can have much greater capacity," said Mr. Egeland.

Mr. Egeland says there will probably never be an accurate figure of the number of people killed by the tsunami. The current estimate stands at around 150,000, with entire areas on the coast of western Sumatra still unaccounted for.

Mr. Egeland said one reason the world was slow to wake up to the devastation along Sumatra's coast was because the tsunami had hit so hard, there was no one to notify authorities.

"In west Sumatra it was really an explosion, like a wall of concrete, exploding on that coast, and many, many, many villages are gone,” he added.  “It's a very low-lying coastal area, you would have to make it to the mountains, which would be one or two or three miles from coast to be safe."

He compared the levels of death and destruction to the worst natural disaster of modern times.

"The biggest natural disaster recorded in terms of casualties is the 1976 earthquake in China. The official casualty figure of that one was 240,000 dead; some say it might have been higher,” he noted.  “I think it will be very high here as well."

Mr. Egeland says well over $2 billion in aid pledges have been received, in what could be the largest such effort in history. That total should rise in response to the flash appeal Secretary-General Kofi Annan is making during his visit to Indonesia.

But Mr. Egeland, who came under fire last week for describing the donor community as "stingy," said he still worries that the aid for tsunami victims may come from funds that would have otherwise been used for disaster relief in other desperately needy regions of the world.

"It would be the ultimate irony," he said "if we started the year with unprecedented global generosity, and end with no money for those most in need in the forgotten and neglected emergencies in Africa."