UN Secretary General Ban Ki-moon has said the Burmese government is showing 'some flexibility' over calls for a scaled-up international relief effort.

Mr Ban, who is visiting Burma, now officially called Myanmar, has made a three-hour helicopter tour of the Irrawaddy Delta, the region that was hardest hit by cyclone Nargis earlier this month.

He said his main concern was to convince the ruling generals to open up to a major international relief effort.

Mr Ban was greeted at airport in Rangoon by Foreign Minister Nyan Win, who then escorted him to the foreign ministry for the first talks of his visit.

During a meeting with Prime Minister Thein Sein, Mr Ban also expressed frustration over the inability of aid workers to bring assistance at the right time to the affected areas.

The two were to meet again later at dinner, and the UN chief is to meet the regime's leader, Senior General Than Shwe, tomorrow in Naypyidaw, a new capital almost 400 km north of Rangoon.

Meanwhile, the first of 10 helicopters contracted by the UN's World Food Programme has arrived in Burma, which is also known as Myanmar, to help speed relief to remote villages hit by the cyclone.

WFP spokesman Marcus Prior said each helicopter will be used to ferry supplies from the main city of Rangoon to distant parts of the Irrawaddy Delta, where many villages are inaccessible by road.

More than 130,000 people died or are missing and more than 2.4m people are in need of food, shelter and medicine following the cyclone.