Yangon: Myanmar's government faced more pressure on Thursday after a US diplomat claimed that the cyclone that struck last week may have killed more than 100,000 people.

The warning came from Shari Villarosa, head of the US embassy in Myanmar, who said that although some aid was getting through, many offers were being spurned.

The government had said that 22,500 people have been killed so far with more than 40,000 missing and up to a million thought to have been left homeless. 

Villarosa said the situation was becoming " horrendous” with a “very real risk” of serious diseases breaking out. 

She said that her claims that the toll could pass 100,000 was based on information from an unnamed non-governmental organization.

The UN World Food Programme says four aircraft loaded with critically needed food from the agency were set to land at Yangon airport on Thursday morning for rapid delivery to the badly affected Irrawaddy delta.