Yangon, Myanmar ? A U.S. plane ferried relief to Myanmar for the first time Monday to help nearly 2 million cyclone victims facing disease and starvation.

Even as the death toll climbed, Myanmar’s authoritarian regime continued to bar nearly all foreigners experienced in managing humanitarian crises from reaching survivors of Cyclone Nargis.

With hundreds of thousands of homes destroyed in the disaster zone, refugees packed into Buddhist monasteries or camped in the open, drinking dirty water contaminated by dead bodies and animal carcasses. Medicine and food were sorely lacking – even as supplies bottled up at the main international airport.

Yangon, Myanmar’s largest city, was pounded by heavy rain Monday and more downpours were expected throughout the week, further hindering aid deliveries. For many, the rainwater was the only source of clean drinking water.

Myanmar’s hermetic authoritarian regime made a huge concession Monday by letting the United States – the fiercest critic of its human rights record – bring in relief following prolonged negotiations.

It appeared to broaden the original agreement for three flights on Monday and today, with a U.S. Marines spokesman saying the flights would continue Wednesday.

The U.S. military C-130 cargo plane filled with 14 tons of water, mosquito nets and blankets was unloaded in Yangon, providing what officials said was help for some 30,000 victims of the May 3 disaster.

It was immediately transferred to Myanmar army trucks to be ferried by air force helicopters to the worst-hit Irrawaddy delta, government spokesman Ye Htut told reporters.

A U.S. second flight carrying over 19,000 pounds of relief took off today.

The United Nations said its first aid convoy arrived Monday evening in Yangon overland from Thailand with more than 20 tons of tents and plastic sheets. Distribution of the U.N. aid began today.