Scientists Yan Xiaoping (left) and Wang Guangdong monitor the position of icebergs aboard Chinese icebreaker Xuelong in Antarctica on Sunday. The ship has been stranded by ice floes since late last week. Zhang Jiansong / Xinhua

"Heavy floes and icebergs are moving fast, and a large iceberg is moving toward us," Wang told a Xinhua reporter on board on Sunday.

Xuelong was locked in a heavy floe area, some 15 km from the nearest ice-free waters, according to the Xinhua reporter.

The vessel can get out of trouble as long as it can break through the thickest floe zone, about 3.7 km long, Wang said, adding that Xuelong is waiting for the right opportunity.

Qu said icebergs and floes are being monitored 24 hours, because a collision with an iceberg may be disastrous.

The Australian Maritime Safety Authority said on Saturday that Xuelong confirmed its safety and said the ship does not require assistance at the time.

It said the Russian and Chinese ships agreed that further assistance from the Australian ship is no longer required and that they will be able to provide mutual support to each other.

The Australian ship will take the passengers rescued by Xuelong to the Australian island state of Tasmania, arriving by mid-January after refueling at Australia's Casey base in Antarctica.

On Friday, President Xi Jinping urged an all-out effort to ensure the safety of Xuelong staff.

Premier Li Keqiang has also instructed crew members aboard Xuelong to stay calm and wait for the opportunity to break out.

Xuelong left Shanghai in early November on China's 30th Antarctic expedition, which was expected to last 155 days. The mission involves scientific research, construction of the country's new research base and the site inspection of another one.

Qu said the expedition will be rescheduled after Xuelong breaks out.

wangqian@chinadaily.com.cn