YANGON, Myanmar (CNN) -- Almost 4,000 people have died and another 3,000 remain missing in Myanmar as a result of this weekend's devastating cyclone, state media reported Monday amid fears that the death toll could continue to soar.

Destroyed fishing boats lay in the port of Yangon after cylone Nargis tore through the city.

Diplomats summoned to a government briefing on Monday said the foreign minister acknowledged that as many as 10,000 could be dead as the reclusive southeast Asian country's ruling military junta issued a rare appeal for international assistance in the face of an escalating humanitarian crisis.

A state of emergency was declared across much of the country following the 10-hour storm that left swathes of destruction in its wake.

The government of neighboring Thailand said Myanmar's leaders had already requested food, medical supplies and construction equipment, AP reported. The first plane-load of supplies was due to arrive Tuesday, a Thai spokesman said.

United Nations Secretary-General Ban Ki-moon said in a statement he was "deeply saddened by the loss of life and the destruction suffered by the people of Myanmar" and pledged to mobilize international aid and assistance as needed.

A United Nations Disaster Assessment and Coordination team is on stand-by to assist the government in responding to humanitarian needs if required, the statement said.

Scenes of the destruction showed extensive flooding, boats on their sides in Yangon harbor, roofs ripped off buildings, uprooted trees and downed power lines after cyclone Nargis battered the Irrawaddy delta with 150 mile (241 km) an hour winds throughout Friday night and Saturday morning, dumping 20 inches of rain. Watch how the cyclone crippled Yangon »

"After about noon, the sky cleared and everybody came out and were just stunned," said Shari Villarosa, U.S. Charge D' Affaires in Yangon. "People on my compound who had been there for about 15 years say they had not seen anything like this here, ever."

Residents of Yangon trudged through knee-deep swirling brown waters Monday as the delta city remained mostly without electricity and phone connections. Watch the cyclone hammer Yangon »

Hakan Tongkul, with the United Nation's World Food Programme, said residents in the capital "need urgent assistance." "This has pushed people to the edge. All that they have has been blown away."

A spokesman for the Red Cross said the emergency aid group was working with its Myanmar agency to provide drinking water, temporary shelters and blankets and warned that urgent action was needed to limit outbreaks of disease.

"I think one of the biggest needs right now is to stave off disease," said spokesman Eric Porterfield. "We will be helping with the distribution of clean drinking water and setting up shelters."

Relief agencies met at the United Nations' Bangkok headquarters Monday to coordinate their response to the disaster. The International Federation of Red Cross and Red Crescent Societies said it had released 200,000 Swiss Francs (about $190,000) to help with the aftermath.

The U.S. aid group World Vision also said it had responded to a government request for assistance.

"The biggest need is getting water for the two million affected people," World Vision spokesman Casey Calamusa told CNN, adding that it was rare for the military government to ask for help. Learn more about Myanmar »

Don't Miss

• Special report:  Crisis in Myanmar
• iReport.com: Are you there? Send your photos, videos

Impact Your World

• See how you can make a difference

A state of emergency was declared Sunday across five regions: the city of Yangon, Irrawaddy, Pegu and the states of Karen and Mon. All flights to Yangon, the former capital, were canceled.

"Most Burmese with whom we've been in touch report they lost their roofs, although so far everyone we have been able to contact reports that they and their families are safe," said a Yangon-based diplomat who requested anonymity because he was not authorized to speak to the media.

Earlier Monday, an editor for an independent Myanmar newspaper based in Thailand told CNN that people in the Southeast Asian nation were angry over the response to the disaster by the ruling military junta.

"People are very angry with the slow response coming from the military government," said Aung Zaw of Irrawaddy news magazine.

Zaw said communication was down across large areas of the country. He also said the casualty figures could rise.

"Very few people have access to these areas to estimate damage and how many people have been killed." Listen to Irrawaddy journalist discuss the situation in Myanmar »

Khin Maung Win, a spokesman for the Democratic Voice of Burma -- a broadcast media group run by opposition expatriates -- said the whole of the delta region had been affected and entire villages had disappeared.

Pictures from inside the country showed a cyclone-ravaged region with tin huts crushed under trees. Bicyclists navigated around large branches that littered the deserted roads.

A man with his pant legs rolled up waded through knee-deep water and strained to clear massive limbs that were blocking the entrance to a house.

"The cleanup is beginning, but this will take a long time," the diplomat said. "The damage around town is intense."

"Fuel is not easily available. International emergency assistance would be needed within seven days. There is no food for eating," Win said.

Food prices -- already rising steeply -- climbed further. Long lines could be seen at gas stations in Yangon. Many of the stations were operating on generators. At one gas station more than 100 buses lined up to refill.

Despite widespread damage, Myanmar's junta plans to proceed with a referendum on the country's constitution on May 10 -- the fourth step of a "seven-step road map to democracy" -- according to state-run media reports.

The government has said elections would be held in 2010 to choose a representative government to replace the military junta.