A makeshift shelter on a street in Rangoon: More than a month after Cyclone Nargis devastated the city and the surrounding Irrawaddy River delta, United Nations helicopters are finally beginning to reach some of the more remote victims of the storm. (Udi Kivity/CBC)

A fleet of helicopters chartered by the United Nations began delivering much-needed food and relief supplies Monday to victims of Burma's devastating Cyclone Nargis.

The massive tropical storm slammed into Burma, also known as Myanmar, last month, leaving more than 130,000 people dead or missing and 2.4 million homeless or evacuated from their communities.

Burma's reclusive military junta has been criticized for refusing to allow a large-scale foreign relief effort, and the first UN helicopters only began arriving in the country in the last few days.

Four choppers ferried emergency aid to remote towns in the Irrawaddy River delta Monday, according the UN World Food Program spokesman Paul Risley, and to the hard-hit towns of Bogale and Labutta, where storm surges and flooding killed tens of thousands.

"These are areas that clearly have not received regular supplies of food or other relief materials," Risley said.

Helicopters are crucial for reaching delta communities that remain cut off by washed-out roads and felled trees.

With safe drinking water one of the most acute needs of survivors, bulky water purification kits have to be transported by helicopter from the airport in Rangoon, the country's largest city and the only place where the government is allowing aid deliveries from abroad.

Still barriers to foreign aid: agencies

Before Monday, only a single UN helicopter was deployed in Burma. Four more aircraft are to be delivered to Rangoon this week from neighbouring Thailand, Risley said.

There are still significant barriers to foreign relief workers, aid agencies say, with the Burmese authorities reluctant to grant permits for aid teams to visit the Irrawaddy Delta.

At first, the government refused almost all foreign help and barred international media from reporting on the crisis. A visit by UN secretary general Ban Ki-moon two weeks after the cyclone struck led to promises that "all aid workers" would be allowed access, but relief agencies say there's little sign of that happening yet.

The military junta is also being criticized for evicting storm victims from refugee camps, but the ruling generals have said such allegations are false and intended to besmirch the country's international image.

Burmese told to 'remain vigilant' and 'nationalistic'

On Monday, all three state-run newspapers carried slogans in bold face type that urged the people of Burma to rally behind the government and not trust what is being reported by foreign news agencies.

Anti-government elements are feeding "the foreign news agencies stories about relief and rehabilitation that they have made up and shot on video," all three newspapers reported.

"Storm victims are hereby warned to remain vigilant with nationalistic spirit," the newspapers said.

With files from the Associated Press