Chinese researchers and mountaineers on a mission to remeasure the earth's summit have to postpone their climbing of Mount Qomolangma, known as Mount Everest in the west, until the weekend because of bad weather, a director of the expedition said Tuesday.

The ascent of the mountain, which straddles the border of China and Nepal, was first scheduled for May 5 but has been repeatedly hampered by wretched weather conditions.

The peak, which according to China's first measurement in 1975 is 8,848.13 meters above sea level, has seen frequent heavy snows and strong winds since early May, which mountaineering experts said is rare in recent years.

They predicted that the weather might turn favorable after May 20.

The climbing endeavor constitutes part of China's scientific research program on Mount Qomolangma, which was launched in March.

The climbers left the base camp at 5,300 meters last week and are now at a camp at 6,500 meters.