Foreign dignitaries have brought welcome promises of help to Indonesia's devastated Aceh region, but they're also creating traffic problems at the area's tiny main airport. The stream of visiting VIPs has clogged the only landing strip and slowed critical aid deliveries, humanitarian workers complained Saturday.

Visits by U.N. Secretary-General Kofi Annan and U.S. Secretary of State Colin Powell have shut provincial capital Banda Aceh's only airport briefly for security reasons, delaying deliveries by incoming aid planes.

"It slows things down," said Maj. Murad Khan, a spokesman for Pakistan's Tsunami Relief Task Force. "I think they need to coordinate that better."

Before the disaster struck, the tiny airstrip handled about three flights each day. Now it is a bustling hub for relief operations and has to cope with dozens of daily flights.

A delegation of American senators and representatives arrived to see Banda Aceh on Saturday. They came by helicopter from the USS Abraham Lincoln aircraft carrier so as not to take up a landing strip slot.

Tim Gerhardson, a spokesman for the U.S. Embassy in Jakarta, said Powell's plane took off again immediately after dropping him off Wednesday so it wouldn't be in the way. The secretary of state toured the area by helicopter and Gerhardson said aid shipments had continued to flow during that time.

On Saturday, U.S. State Department spokesman Richard Boucher said, "Our visit was carefully organized to avoid any interference with the relief operations. In fact, relief planes landed while we were there and at no time did we try to close down movement into Banda Aceh."

Michael Elmquist, the U.N. official in charge of operations in Sumatra, did not answer a call seeking comment on Annan's visit.

Maj. Gen. Bambang Darmono, Indonesia's military commander for Aceh, said there was "no policy" on closing the airport completely but standard security procedures required that flights be "reorganized" around the visits of dignitaries.

An Asian diplomat from a country with a military relief mission in Aceh, where more than 104,000 people died in the huge quake and subsequent tsunami, called it "a difficult situation."

Pierre King, of the International Organization of Migration aid group, said there was no way around the problem.

"It's horrible, but what can we do?" he asked, noting that the airport closures had not affected his group, an organization of 104 countries helping to deliver food and treat injured survivors. "I had my stock already, thank God, so I didn't stop working."

The International Organization of Migration said it was organizing the first truck convoy to carry supplies to the stricken region from Jakarta on Monday because the airport is so busy.

Also Saturday, the United Nations said it had begun a mammoth effort to feed up to 2 million survivors of the disaster around southern Asia, focusing particularly on young children, pregnant women and nursing mothers.

World Food Program Executive Director James Morris said at a Jakarta news conference that the operation would likely cost US$180 million for six months.

"Many of the places where we work are remote, detached and their infrastructure has been dramatically compromised," Morris said, a day after he visited Aceh with Annan. "We will be distributing food ... by trucks, by barges, by ships, by helicopters, by big planes."

He said the agency has now dispatched enough food in Sri Lanka to help feed 750,000 people there for 15 days.

Jeff Taft-Dick, WFP country director in Sri Lanka, said that was a critical milestone "because there is now enough food around the country to feed everyone who needs it."

Morris said the agency was feeding 150,000 people in Indonesia and expected that to increase to 400,000 within a week and possibly reach as high as a million eventually.

A detachment of 54 U.S. Marines got to work on tsunami relief in the Sri Lankan village of Pitiwella, near the hard-hit city of Galle, using a bulldozer to clear piles of debris.

An American Navy ship, the USS Duluth, is expected to arrive off the southern coast of Sri Lanka in the next day or two to provide more help, and helicopters will ferry ashore another 116 troops from the 15th Marine Expeditionary Unit as well as equipment, Lt. Col. Edmund Bowen said.

"It's good that the Marines are here. The damage is so bad that we can't do it alone," said D.V. Chaturanga, who lost his grandmother and his home to the waves.

The huge Dec. 26 earthquake and tsunami killed more than 150,000 people across southern Asia and as far as east Africa.

Meanwhile, Thailand on Saturday declined an offer from Japan of US$20 million in emergency relief, saying the assistance should be directed to countries more in need.

The U.S. military said there were 13,000 American troops helping in the tsunami-hit region, at a cost of US$5.6 million a day.

Helicopters from the USS Abraham Lincoln aircraft carrier group had their biggest aid delivery day, bringing 125,000 pounds of food, water and other supplies to Aceh aboard 15 helicopters.