With the toll of dead and missing now more than 133,000 people, about 2.5 million people are clinging to survival in the storm-ravaged Irrawaddy delta but the military government has refused to admit large-scale outside relief.
"This is inhuman," Brown told the BBC World Service in an interview broadcast on Saturday. "We have an intolerable situation, created by a natural disaster.
"It is being made into a man-made catastrophe by the negligence, the neglect and the inhuman treatment of the Burmese people by a regime that is failing to act and to allow the international community to do what it wants to do.
"The responsibility lies with the Burmese regime and they must be held accountable."
Brown said his government had considered air-drops of aid. "We rule nothing out and the reason we rule nothing out is that we want to get the aid directly to the people," added Brown.
