US icebreaker to help two stuck ships

An American icebreaker will attempt to free two ships stuck in ice in Antarctica.

Twenty-two crew remain on board the Russian ship Akademik Shokalskiy, which sparked a rescue mission after a blizzard pushed sea ice around the ship and froze it in place on Christmas Eve.

The 52 scientists and tourists on board the research ship were airlifted to safety last week, thanks to the help of the Chinese icebreaker Xue Long.

Those passengers are now on board Aurora Australis on their way to Australia's Antarctic base Casey Station and then Tasmania.

But shortly after the rescue, the 101 crew of the Chinese icebreaker that provided the helicopter that airlifted the passengers on the Russian ship to safety itself became beset by thick ice.

The Australian Maritime Safety Authority (AMSA) said on Sunday that the US Coast Guard's icebreaker Polar Star is now on its way to help.

The Polar Star has been en route from Seattle to Antarctica since December 3 with a plan to clear a navigable shipping channel in the region.

An AMSA spokeswoman said they will delay this job to help the two stuck ships.

The icebreaker will leave Sydney on Sunday.

It will take about seven days for the US icebreaker, with a crew of 140 people, to reach Commonwealth Bay.

The AMSA spokeswoman said the US ship had greater capabilities than the Russian and Chinese vessels.

"It can break ice over six metres thick, while those vessels can break one-metre ice," she told AAP on Sunday.

"The idea is to break them out, but they will make a decision once they arrive on scene on the best way to do this."

AMSA will be in regular contact with the relevant US Coast Guard and the captain of the Polar Star during its journey to Antarctica.