Anti-whaling group Sea Shepherd says it will expand its fleet to South Korea's coastal waters to prevent whaling in the region.
Ian Campbell, from the Sea Shepherd advisory board, said the Australian government's inaction on whaling has forced the group to extend its activities from the Southern Ocean up to the coast of South Korea.
"We are going to have to find enough ships and enough money to head up to South Korea ... due to the Australian government's lack of action on this over the past three or four years," Mr Campbell told the Seven Network on Friday.
South Korea announced plans to resume its whale slaughter at a meeting of the International Whaling Commission in Panama on Thursday.
It will allow the hunting of minke whales in its coastal waters by exploiting the same legal loophole the Japanese rely on to conduct their controversial scientific whaling program.
Prime Minister Julia Gillard said she was disappointed by South Korea's surprise move and has instructed Australia's top diplomat in Seoul to lodge a protest.
But Mr Campbell said it was "too little and it's far too late".
"This government, sadly for the whales of the world, effectively pulled up a white flag and entered a truce with the Japanese back in about 2008 when they decided not to have any more votes at the International Whaling Commission."
While he said neither John Howard's government nor the current Labor government has been particularly successful, he had "no doubt" that had Australia maintained pressure on Japan, South Korea would not be planning to resume whaling.
Federal Employment and Workplace Relations Minister Bill Shorten said the government would be placing pressure on South Korea.
"The first step is what we said we were going to do, which is talk diplomatically and we can - if everything fails in the talks - take them to the international Court of Justice," Mr Shorten told the Seven Network.
Shadow Treasurer Joe Hockey said the opposition supported the government's moves to use diplomacy to prevent South Korea killing whales.
