YANGON (Reuters) - U.N. Secretary-General Ban Ki-Moon will travel to Myanmar this week to try to speed up troubled cyclone relief, his spokeswoman said on Sunday, as signs mounted of a breakthrough in getting aid to survivors.

Ban's spokeswoman Michele Montas also said she expected there would be an international conference in Bangkok on May 24 to marshal funds for the relief effort in the former Burma.

Ban should arrive in the military-ruled Southeast Asian country on Wednesday evening and travel to the Irrawaddy delta, the area hit hardest by Cyclone Nargis on May 2, she said.

"The objective of the trip is to dramatically accelerate the flow of disaster relief," Montas said.

Britain's Asia minister, Mark Malloch-Brown, said a turning point could be near on a framework to accelerate international aid to up to 2.5 million desperate survivors of the cyclone that left at least 134,000 people dead or missing.

"But, like all turning points in Burma, the corner will have a few 'S' bends in it," Malloch-Brown told Reuters.

Than Shwe, the reclusive leader of junta, made a public appearance on Sunday for the first time since the disaster.

Ban hoped to meet senior members of Myanmar's government, Montas said, but she could not immediately say whether Than Shwe would be one of them. The general has refused to talk to Ban by telephone since the cyclone.

Aid has been trickling in but the junta, suspicious of the outside world, has been reluctant to admit major foreign relief operations and the workers to run them.

The World Food Programme (WFP) said it had managed to get rice and beans to 212,000 of the 750,000 people it thinks are most in need.

DEATH TOLL COULD RISE

State television showed Than Shwe meeting in Yangon with ministers involved in the rescue effort and touring some cyclone-hit areas in the immediate vicinity.

The junta, which has ruled Myanmar in various incarnations for 46 years, moved the capital to Naypyidaw, 400 km (250 miles) north from Yangon, the former Rangoon, in 2005. Than Shwe has rarely been seen in public since.

The United Nations' chief humanitarian officer, John Holmes, arrived in Yangon on Sunday night and was expected to deliver a message from Ban to the generals.

Ban previously proposed a "high-level pledging conference" to deal with the crisis, as well as having a joint coordinator from the United Nations and Association of Southeast Asian Nations (ASEAN) to oversee aid delivery.

Analysts speculated Than Shwe's appearance in Yangon meant he was likely to meet Holmes or possibly Ban.

Thousands of children could die within weeks if food does not get to them soon, the aid organization Save the Children said on Sunday. Malloch-Brown said the United Nations estimated that help had reached less than 25 percent of those in need.

In the last 50 years, only two Asian cyclones have exceeded the human toll of Nargis -- a 1970 storm that killed 500,000 people in neighboring Bangladesh and another that killed 143,000 people in 1991, also in Bangladesh.

If Myanmar's junta does not open its doors to a large-scale aid operation like the one after the Asian tsunami in December 2004, disaster experts say the death toll from Nargis could climb dramatically.

At least 232,000 people were killed when the tsunami struck nations bordering the Indian Ocean.

Malloch-Brown, who came to Yangon after visiting some ASEAN members, said the Asian/U.N.-led process had already begun.

Asian nations considered friendly by Myanmar were sending in aid teams and an ASEAN assessment team was on the ground, he said. That team is due to report to a meeting of foreign ministers from ASEAN, of which Myanmar is a member, in Singapore on Monday.

Other countries would make their contributions through this channel, Malloch-Brown said.

Despite his optimism about a possible breakthrough, he said that, because of the junta's suspicions, operations were still unlikely to involve numbers of foreign aid workers comparable to other recent disasters in Asia.