May 21 (Bloomberg) -- Myanmar's military regime will bear the blame for the deaths of more of its people if it continues to deny access to international aid workers in the aftermath of Tropical Cyclone Nargis, a U.S. envoy to the region said.

Almost three weeks after Nargis struck the country formerly known as Burma, the relief effort faces ``critical shortages'' in doctors, public health specialists and helicopters and pilots to deliver aid, Scot Marciel, the U.S. ambassador to the Association of Southeast Asian Nations, told a congressional hearing in Washington yesterday.

``The door must be opened far wider and rapidly to prevent a second catastrophe,'' he said. ``If assistance and expertise is not allowed in, and thousands of Burmese perish, the responsibility for this catastrophe will fall squarely on the shoulders of Senior General Than Shwe and the other Burmese leaders.''

More than 130,000 people are dead or missing after the cyclone struck May 3, destroying villages and decimating crops in the southern Irrawaddy River delta. The United Nations says that only a quarter of the 2.4 million people in need of aid have been reached.

The junta agreed two days ago to allow regional allies to funnel aid into the delta, and the 10-member Association of Southeast Asian Nations is preparing to send workers to distribute international supplies.

`Appalling' Response

``We welcome Asean's efforts, but at this point we don't know yet whether the Burmese regime is actually going to allow them to bring in the experts, the equipment and other international help,'' said Marciel, adding the junta's response to the disaster is ``appalling.''

The military government won't accept any U.S. warships to dock because it would come with ``strings attached,'' said the state-run New Light of Myanmar newspaper, which didn't elaborate, according to the Associated Press.

The U.S. Navy is nevertheless keeping four vessels nearby in hopes the regime will have a change of heart.

``It is very hard to turn your back and leave,'' Defense Department spokesman Bryan Whitman said today at a Pentagon briefing in Washington.

Myanmar continues to accept U.S. aid shipments. Four military transport planes delivered supplies, Whitman said. That brings to 40 the number of such flights, which are made by C-130 aircraft and have delivered a total of 367 metric tons of aid to Myanmar.

Ban's Trip

The country's generals, who have ruled the nation of 48 million people since 1962, insisted they could handle the distribution effort themselves and barred international aid workers from traveling to the delta from the former capital, Yangon.

Asean has long been criticized by Western nations for failing to press Myanmar, which is a member, to restore democracy and censure the junta for human rights abuses. The group includes Brunei, Cambodia, Indonesia, Laos, Malaysia, Philippines, Singapore, Thailand and Vietnam.

UN Secretary-General Ban Ki-moon, who is scheduled to arrive in Myanmar tomorrow, said the relief effort has reached a ``critical moment.''

Ban said he aims to meet with Than Shwe and work with the junta and Asean to ensure the disaster response is coordinated.

Expediting Visas

``We have received permission to operate nine World Food Program helicopters, which will allow us to reach areas that have so far been inaccessible,'' Ban told reporters in New York yesterday before leaving for Myanmar. ``I believe further similar moves will follow, including expediting visas of relief workers seeking to enter the country.''

He pointed to potential longer-range food shortages for Myanmar due to the cyclone, which he said caused as much as $10 billion in losses, especially to the rice-growing delta.

``It may already be too late to plant the next harvest,'' Ban said of rice planting that usually begins in June. ``This will compound the present crisis. The economic effects could be more severe and long-lasting'' than the 2004 Indian Ocean tsunami that killed 220,000 people.

The official death toll stands at 77,738 and 55,917 people are missing, the UN Office for the Coordination of Humanitarian Affairs said in its latest situation report yesterday.

The majority of people forced from their homes are sheltering in Buddhist monasteries, while others are staying in tented camps run by the government, according to the report. Medical teams from Thailand, India, China and Laos are working with the Myanmar health service in affected areas, it said.

``Humanitarian assistance remains inconsistent and really needs to be scaled up,'' the UN news service IRIN cited OCHA spokeswoman Amanda Pitt as saying yesterday from Bangkok.

To contact the reporter on this story: Ed Johnson in Sydney at ejohnson28@bloomberg.net.

Last Updated: May 21, 2008 12:16 EDT