An Asean assessment report on the cyclone is due in mid-July but speaking in Yangon on Tuesday the group's secretary-general said assessment teams had had "unlimited and unfettered" access to the disaster region.
"The basic needs of the victims are being met for their early recovery," Surin Pitsuwan said.
Cyclone Nargis tore a deadly path through the Irrawaddy Delta region of central Myanmar, leaving more than 84,000 dead according to the latest figures from the country's military government.
Aid agencies say almost half the food stocks in the cyclone-affected areas were destroyed by the storm - a region that had been known as the "rice bowl" of Myanmar because of its fertile rice fields.
The World Food Programme has said its available rice supplies in the country will only last until the end of June.
Myanmar's military government was widely criticised by aid agencies and the UN for its slow response to the disaster and its unwillingness to allow access to international aid teams in the crucial early days after the storm.
But in a speech on Tuesday, Kyaw Thu, Myanamar's deputy foreign minister, said the government had seen "less and less requests for emergency assistance coming from communities and local authorities" in the Irrawaddy Delta region.
"Various reports indicate that the worst of the crisis may have stabilised, although it is by no means over."