WELLINGTON (AFP) -- New Zealand Prime Minister Helen Clark warned that the world would not forgive Japan if it failed to move a crippled whaling ship and consequently caused an environmental disaster.

The Nisshin Maru has been disabled in Antarctic waters since a fire broke out on Thursday prompting fears of an oil spill.

The ship is carrying more than 1.3 million litres of fuel and lies just 100 kilometres (60 miles) from the world's biggest Adelie penguin colony at Cape Adare on the Antarctic coast.

Clark said she understood both Greenpeace and an American icebreaker had offered assistance but that the Japanese had said they could cope.

"They'd better be right because no one would forgive them for an environmental accident which causes huge damage to that pristine area," she told radio Newstalk ZB. "My advice is if you can't see a way of getting that boat out of there without some help either from the American vessel or from Greenpeace or from somebody else, the world is going to be very upset if there's a major spill in that area."

A spokesman for the New Zealand rescue coordination centre, Steve Corbett, said the risk of an environmental disaster was "relatively low".

Though an encroaching pack ice was a threat, the ship was drifting north and was about 16 kilometers from the ice.

Corbett said the Nisshin Maru would probably not need a tow from the Greenpeace ship Esperanza, a former Soviet tug.

The Japanese whalers have six vessels there and "they should be able to rig up some sort of arrangement", he said. But he added the ships would be more vulnerable to the ice and less maneuverable if they were lashed together.

The whalers were Monday continuing to make repairs to the ship and dampen down hotspots from the fire which claimed the life of one crewman.