An Australian soldier who was trapped in sub-zero conditions on New Zealand's Mount Aspiring has been rescued in a "snatch and grab" mission involving three helicopters.

Key points: The soldier, identified as Lt Terry Harch, was found by rescue teams on Thursday and rescued on Friday

The soldier, identified as Lt Terry Harch, was found by rescue teams on Thursday and rescued on Friday He is said to be in a "reasonable" condition after being rescued

He is said to be in a "reasonable" condition after being rescued Lt Harch began his climb last Friday, and the alarm was raised on Monday

Terry Harch had been stranded on the mountain, located on New Zealand's South Island, since a severe snowstorm hit the area last weekend.

"It's a great result as we did not want the climber spending another night on the mountain. The aim now is to get him to hospital for immediate treatment," Neville Blakemore of the Rescue Coordination Centre New Zealand said.

"This has been a long and drawn out Search and Rescue Operation and the cooperation, skills and expertise shown ... has been nothing short of fantastic," he said.

A representative from Maritime NZ described Lieutenant Harch's condition as "reasonable" but confirmed he had suffered frostbite.

Mt Aspiring has a height of 3,033 metres, and the point where Lt Harch was found, Quarterdeck Pass, sits at about 2,280 metres.

Mt Aspring is popular among climbers, but has also proven dangerous and has been the site of numerous deaths.

Four members of the Wanaka Alpine Rescue Crew stayed with the 29-year-old at Quarterdeck Pass overnight, after a helicopter found him alive "with slight frostbite" at 5:00pm on Thursday.

Lt Harch has previous climbing experience, and previously climbed New Zealand's highest mountain — the 3,724m Mount Cook — for military charity Soldier On.

Mr Harch has endured winds of up to 60kph, freezing conditions and at times heavy snow. ( Flickr: Geee Kay )

Earlier, Rescue Coordination Centre New Zealand senior search and rescue officer Geoff Lunt praised Lt Harch's survival techniques.

"The climber has been sheltering for the past two nights at [Quarterdeck Pass] and he has clearly made some good decisions to be able to survive the bad weather, heavy snow and high winds," Mr Lunt said.

"The rescue team left with the climber had provided warm clothing, tents, food and were well-equipped with emergency gear to keep the party dry and warm for what, is hoped to be, their last night on the mountain."

Mr Lunt told Radio Lt Harch would have likely used his skills learned in the Army to survive.

"We think he dug himself a snow dug-out shelter and that's helped in his survivability over these last few days," he said.

Lt Harch entered the national park last Friday and is thought to have left his heavier gear behind to make a quick ascent — a usual practice among climbers — before being caught out by the weather.

The alarm was raised on Monday and rescue crews watched his beacon moving around the mountain for days as concerns grew.

ABC/AAP