A helicopter may be used to rescue the 74 people on board a research ship stranded in pack ice off East Antarctica.
The MV Akademik Shokalskiy became stuck in pack ice about 100 nautical miles east of the French base Dumont D'Urville, more than 1500 nautical miles south of Hobart, during a blizzard on 24 December.
The Australian Maritime Safety Authority says an Australian vessel, Aurora Australis, is due to arrive in the area by Sunday evening, and if it can't get through the ice an air rescue might take place.
There is a helicopter on board the Chinese icebreaker Xue Long (Snow Dragon), which came within six and a half nautical miles of the stranded ship on Friday, before having to stop because of the ice.
There are 74 people, including six New Zealanders, on board the Akademik Shokalskiy for a "Spirit of Mawson" voyage, which is retracing Sir Douglas Mawson's Antarctic expedition 100 years ago.
An expedition leader, Chris Turney of the University of New South Wales, said the weather had improved and there was no longer a blizzard. He said the passengers are well but frustrated, and want to be rescued.
Professor Turvey said seeing Xue Long so close has helped to lift people's spirits.