A top US diplomat has warned 100,000 people may have lost their lives after a cyclone hit Burma.

Huge swathes of the country remain flooded four days after it was ravaged by winds, floods and 12ft-high tidal waves and satellite images reveal coastal regions have changed beyond recognition.

Shari Villarosa, charge d'affaires of the US embassy in Rangoon, said: "The information that we're receiving indicates that there may well be over 100,000 deaths in the delta area."

She said the figure was based on estimates provided by an unnamed international non-governmental organisation.

State radio and television has reported an updated death toll of 22,980, with 42,119 missing and 1,383 injured in the wake of Cyclone Nargis.

"We estimate upwards of one million people currently in need of shelter and life-saving assistance," said Richard Horsey, spokesman for the United Nations Office of the Coordination of Humanitarian Affairs.

"There are large swathes of the lower Irrawaddy delta completely under water. We are talking 5,000 sq km (1,930 square miles) under water. It's a vast area."

With the delta region virtually cut off and frustration growing among aid agencies, French Foreign Minister Bernard Kouchner suggested the international community enters the country without waiting for approval from the Burmese military.

The UN has a "responsibility to protect" civilians and the Security Council can authorise action even if it means violating national sovereignty.

But John Holmes, UN undersecretary-general for humanitarian affairs, said "useful and constructive discussions" were taking place with the authorities to get them to waive visa and customs requirements to get aid workers and supplies to stricken areas.

The UN announced it will release at least £5 million from its emergency relief fund for Burma and will soon launch an appeal to raise more.

© Independent Television News Limited 2008. All rights reserved.