YANGON (AFP) - Myanmar has said that more than 133,000 people were dead or missing in the cyclone disaster, nearly doubling the official toll two weeks after the storm left the country's rice-growing south in ruins.

The announcement came as Myanmar's military rulers, welcoming aid from abroad but suspicious of the outside world, again rejected calls to let foreign experts direct the massive relief effort for 2.5 million needy survivors.

State television put the latest toll at 77,738 dead and 55,917 missing -- numbers close to estimates by international aid groups in recent days as the full scope of the destruction in the Irrawaddy Delta becomes known.

The news bulletin said the government had not been able to confirm the increase earlier due to the widespread damage as well as subsequent heavy rains, which have deepened the misery in one of the world's poorest nations.

It said 19,359 people were injured. Among government personnel, there were 159 dead, 58 missing and four injured. No other details were given.

In the USA lawmakers asked President George W. Bush on Friday to consider "humanitarian intervention" in the cyclone-hit country after its military rulers refused to allow foreign experts to direct relief efforts despite the rising death toll.

Forty-three members of the House of Representatives wrote to Bush asking him to "strongly consider" backing efforts by France, Britain, Germany, Denmark and other nations to gain entry into the devastated Irrawaddy Delta region "to provide urgent life-saving humanitarian aid."

The US political drive came as international rights group Human Rights Watch condemned the results of Myanmar's constitutional referendum as "fatally flawed" on Friday and urged foreign governments to reject its legitimacy.

State television reported on Thursday that Myanmar's military-backed constitution was approved by 92.4 percent in a referendum held everywhere except regions hardest hit by the deadly cyclone two weeks ago. Those areas will vote May 24.

The junta has continued to insist it can manage the catastrophe alone, despite urgent international pleas to open up their doors and avert a second wave of death among desperate victims short of food, water, shelter and medical care.

But while the generals have accepted hundreds of tonnes of relief supplies -- from high-tech foodstuffs used in famine regions to the most basic needs like fresh water -- they have rebuffed foreign disaster management experts.

Instead, the secretive regime has all but sealed off the disaster zone, keeping out most foreigners and insisting that the country can rebuild on its own.

Louis Michel, the European Union's humanitarian aid commissioner, concluded a two-day visit on Friday but was unable to visit the delta -- a main rice-growing region in the country, formerly known as Burma.

But he said that more than 100 doctors from neighbouring countries would go into the country on Saturday, and stressed that time was running out to prepare for the October rice harvest in the country.

"Time is life," he said in Bangkok after the trip.

"Every possible pressure -- all rhetorical and diplomatic means -- must be used to get them to understand that they must help us help them," Michel said of the junta in an interview with AFP TV in neighbouring Thailand.

He had previously warned that the country, once a rich British colony, is at risk of famine after Cyclone Nargis, which hit May 2-3, wiped out vast swathes of paddies and destroyed rice stocks.

Meanwhile Western diplomats who declined to be named said the regime was taking them to the delta on Saturday, but had no further details about where they would be going.

"We're not expecting to be shown the real picture or be given any freedom to see what we'd like to see," one diplomat said.

The military, which has ruled Myanmar for nearly 50 years, keeps a tight rein on all aspects of life here -- and Michel said he had put a series of requests to authorities to ease the relief effort.

Among the requests, he said, was for local Burmese staff working for aid groups to be able to go back and forth freely into the disaster zone, rather than get individual permission from authorities.

"They are tempted to react positively to our requests," he said.

"But I feel also reluctance because the relationship between authorities and the international community (is) of course not very positive. So they are hesitant."

Later it was confirmed United Nations humanitarian affairs chief John Holmes would arrive in Yangon Sunday for talks on relief aid after securing a visa.

Holmes is being sent by UN chief Ban Ki-moon to push Myanmar's military leaders to open the country up more to international assistance.

Myanmar's southeast Asian neighbours meanwhile were gearing up for talks in Singapore on Monday aimed at convening a high-level donors meeting.

A UN source said a donor meeting would likely take place in southeast Asia, probably Bangkok, with May 24 suggested as a possible date.