A Chinese icebreaker trying to reach a Russian ship trapped in Antarctica has been halted by thick ice within sight of the stricken vessel, a passenger and Australian rescue officials said,

The Snow Dragon was one of three icebreakers dispatched to free the MV Akademik Shokalskiy, which became stranded far south of Tasmania on Tuesday in ice driven by strong winds.

"Unfortunately Snow Dragon can't get through. It's standing by and waiting on another vessel to help. Everyone (is) well," Chris Turney, an Australian professor who helped organize the voyage on the Russian ship, said via Twitter on Saturday

Earlier, Turney posted a photograph apparently showing the Chinese vessel, a speck on the horizon beyond an expanse of ice.

"It has encountered heavy ice and it's not safe for them to continue to the Russian vessel for their own safety," Andrea Hayward-Maher from the Australian Maritime Safety Authority, which is coordinating the rescue effort, told the Australian Broadcasting Corp.

"The master of the vessel needs to consider the safety of his crew and his vessel as well. We'll be looking at other options today."

The stranded passengers might have to wait for Australia's Antarctic resupply ship, the Aurora Australis, which was not expected to arrive until Sunday.

The Akademik Shokalskiy departed New Zealand on Nov. 28 on a privately funded expedition to commemorate the 100th anniversary of an Antarctic journey led by famed Australian explorer Douglas Mawson.

The ship's 74 passengers include scientists and tourists, many of them Australian, and what the Russian Foreign Ministry said were 22 Russian crew members.

The Russian embassy in Australia has been in constant contact with the captain and said everyone on board was in good health and there was "no threat to their lives or safety".

The ship is trapped some 100 nautical miles (185 km) east of French Antarctic station Dumont D'Urville and about 1,500 (2,800 km) nautical miles south of Hobart, Tasmania.