Search efforts for the helicopter - carrying three people including a Thai pilot - will continue on the ground as hopes fade of finding the climbers alive after they lost contact with their team in early September.

"We have stopped our aerial search operation because of very bad weather. Snowfall is very heavy on the mountain," said an official close to the rescue operation who did not want to be named.

"We will continue searching on the ground as much as we can."

The Thai helicopter, part of a search team funded by U Tay Za, chairman of the Htoo Group, lost contact with ground control last Saturday shortly after it took off from Putao airport in northern Kachin state to drop supplies to the rescue teams.

The missing climbers, Aung Myint Myat and Wai Yan Min Thu, lost contact with the rest of their team in early September after reaching the summit of Hkaka Borazi in Myanmar's portion of the Himalayas.

"There is very little chance of finding the two missing mountaineers alive in this weather. It's possible that they have been covered up in heavy snow," said another official who wished to remain anonymous.

"At this moment, we are only focusing our search on the missing helicopter from Thailand."

The search operation is being led by Myanmar's Htoo Foundation, the charitable arm of the sprawling Htoo Group of Companies, with interests from agriculture to an airline.

The tycoon, who is blacklisted by US sanctions, launched a rescue mission to the mountain, which is in an area where he narrowly survived a helicopter crash a few years ago.

In a statement on its website the Htoo Foundation said it had called off the aerial search due to poor weather conditions.

Hkaka Borazi, in Kachin state, is 5,881 metres (19,295 feet) high.