All 52 passengers were airlifted Thursday from a Russian research vessel icebound in Antarctica and are safe on board an Australian supply ship, rescuers said.

"Aurora Australis has advised AMSA that the 52 passengers from the Akademik Shokalskiy are now on board," the Australian Maritime Safety Authority said.

The helicopter evacuation of a Russian research ship stranded in Antarctica was launched Thursday after a series of stalled attempts due to bad weather and sea ice.

"The Chinese helicopter has arrived at the Shokalskiy. It's 100 percent we're off! A huge thanks to all," tweeted expedition leader Chris Turney.

Turney's post was accompanied by a video showing a red helicopter from the Chinese icebreaker Xue Long touching down on a landing pad marked out on the ice beside the Akademik Shokalskiy, which has been stranded in pack ice in Antarctica since December 24.

An orange-suited rescue crew from the Chinese ship disembarked onto the ice before the helicopter again took off.

"If it all goes well we'll be off in about an hour's time," Turney said on the film.

The Australian Maritime Safety Authority (AMSA) said it was still awaiting formal confirmation from the Xue Long that the rescue operation had begun.

AMSA estimates that the rescue of the ship's 52 passengers, which include scientists, tourists and journalists, will take at least five hours, depending on the weather.

The group will be moved in five flights of up to 12 passengers, with each return journey to the Xue Long some 10 nautical miles distant expected to take 45 minutes.

Under the aerial rescue plan outlined by AMSA earlier Thursday the passengers will be moved from the Xue Long to Australia's Antarctic supply ship the Aurora Australis via a barge.

It will be some weeks before the passengers reach dry land, with the Australis needing to travel via Australia's Casey Antarctic base to refuel.