The charity says children urgently need the correct nutrients
Thousands of children in Burma will starve to death within weeks unless food supplies reach them soon, a UK charity has warned.
Save the Children believes 30,000 under fives in the Irrawaddy Delta area were already "acutely malnourished" before Cyclone Nargis hit on 2 May.
It warns energy-rich food now needs to reach them "before it is too late".
Burma's government has restricted aid distribution to victims of the cyclone, said to have killed at least 78,000.
Another 56,000 people are officially reported missing in the country.
Save the Children UK's chief executive, Jasmine Whitbread, said the charity was concerned children in the worst affected areas were suffering from "acute malnourishment" - the most serious level of hunger.
"When people reach this stage they can die in a matter of days," she said.
"Children may already be dying as a result of a lack of food. They urgently need nutrient and energy-rich food, and food containing all the elements of a balanced diet."
She said the charity was working "flat out" to deliver the aid needed and had already reached more than 140,000 people.
But she added: "We need to reach more before it is too late."
Lack of rice
Save the Children has also warned the victims of the cyclone could remain dependent on foreign assistance until October 2009.
The cyclone has filled rice fields in the Irrawaddy Delta - known as the country's rice bowl - with sea water, destroying vital crops.
Many of the farmers have also been unable to sow seeds in time for the monsoon harvest.
The charity says it is attempting to distribute seeds to those growers whose land is no longer flooded.
On Saturday, Gordon Brown accused Burma's government of "inhuman behaviour" for not allowing international aid to reach the cyclone victims.
The prime minister told the BBC that a natural disaster had been turned into a "man-made catastrophe" because of the negligence of the ruling generals.
France has said Burma is on the verge of committing a crime against humanity after the ruling junta refused to allow in French and US aid ships which are waiting off the coast.
UN humanitarian envoy John Holmes is travelling to Burma to urge the generals to grant more access to UN workers to help with the relief efforts.
He will carry a letter from UN Secretary General Ban Ki-moon to Burma's leader, Than Shwe, who has refused to answer Mr Ban's calls.
UK Foreign Office Minister Lord Malloch-Brown has told the BBC the international community was trying to organise a team of Asian and UN aid workers in the hope this will be more acceptable to Burma's rulers.
The Association of South East Asian Nations (Asean) is due to meet on Monday, with plans for an aid donors' conference likely to be discussed.