WASHINGTON - THE US military has received a 'verbal okay' for five more C-130 relief flights into Myanmar but is pressing for permission to use helicopters to distribute supplies to cyclone-stricken areas, a senior US military official said on Wednesday.

Myanmar's military government has not yet approved helicopter flights or larger flows of international aid, apparently for fear of losing control, said the official, who spoke on condition of anonymity.

But he warned it risk outbreaks of civil unrest if it does not move more quickly to open up.

'I think what you're going to start seeing is that people are going to start rising up,' said the official, who spoke to reporters on condition of anonymity.

'As this continues to go people are going to start finding out that their government is not doing the best they can,' he said.

So far, eight flights by US military C-130s have been allowed into the country over the past three days with tons of food, water, plastic sheeting and mosquito nets.

'We're planning to do another five (flights) early morning, our time frame. We've had verbal okay to do that. What we were trying to do is get helicopters in there as well,' he said.

He said the US military is in the process of setting up refuelling operations for helicopters at an airfield at Mae Sot near Thailand's border with Myanmar and about 400 kilometers from Yangon.

Six CH-53 heavy lift aircraft would then be able to fly directly to areas affected by the storm, which killed at least 34,000 people and left another 30,000 missing, he said.

Helicopters and landing craft also could move from the USS Essex and three other US warships that are now 30 nautical miles off the coast of Myanmar, he said. -- AFP