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 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,'' Campbell told the Seven Network in Australia.
South Korea announced plans to resume its whale slaughter at a meeting of the International Whaling Commission in Panama yesterday.
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.
New Zealand's Foreign Affairs Minister called the plan a "serious setback" in international conservation efforts.
"The portrayal of this initiative as a 'scientific' programme will have no more credibility than the so-called scientific programme conducted by Japan, which has long been recognised as commercial whaling in drag," McCully said.
McCully said he hoped South Korea's leaders would consider the concerns of New Zealand and other countries before making a final decision.
"Any action by Korea to commence whaling in these waters following today's announcement will have serious consequences," he said.
He said if they went ahead with it, "I believe there will be strong and public outcry around the world."
Australian 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 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,'' Shorten said.
- AAP and Fairfax