WELLINGTON - TWO Japanese climbers stranded by atrocious weather on New Zealand's highest peak for five days may not be rescued before the weekend, searchers said on Wednesday.

Driving winds and near-zero visibility on Wednesday thwarted rescuers trying by helicopter to reach the men trapped near the top of Aoraki, also known as Mount Cook.

Attempts to drop them supplies also failed when the chopper was unable to get close enough in the conditions, police said.

One of the two men, believed to be in their 40s, was seen waving to a helicopter on Tuesday morning after their red tent was spotted on the mountain's Empress Plateau, above 3,700m.

'We don't know what food and rations (they have), we don't know the medical conditions,' police constable Stu Mori said.

Inspector Dave Gaskin said the situation was very similar to one of New Zealand's most famous Mount Cook rescues.

Local climbers Mark Inglis and Phil Doole spent 13 days trapped in bad weather near Mount Cook's summit in 1982. Both men lost their lower legs to frost bite after eventually being rescued by helicopter.

The 3,754m Mount Cook attracts hundreds of climbers each year but can be treacherous - some 150 people have died since it was first conquered in 1894. -- AP