Japan has cancelled its Antarctic whaling hunt for the first time in more than 25 years, just days after the UN's International Court of Justice ordered an end to the controversial practice.
"We have decided to cancel research whaling (in the Antarctic) for the fiscal year starting in April because of the recent ruling," a fisheries agency official told AFP.
But he added that "we plan to go ahead with research whaling in other areas as scheduled", including the northern Pacific.
On Monday, the Hague-based ICJ issued a landmark ruling that found the Antarctic programme was a commercial activity disguised as science, and said Tokyo must revoke existing whaling licences.
Australia, backed by New Zealand, hauled Japan before the ICJ in 2010 in a bid to end the annual Southern Ocean hunt.
Tokyo has used a legal loophole in the 1986 ban on commercial whaling that allowed it to continue slaughtering the mammals, ostensibly so it could gather scientific data.
However, it has never made a secret of the fact that the whale meat from these hunts can end on dining tables.
Japan also has a coastal whaling programme that is not covered by the ban.
The next Antarctic hunt would have started in late 2014. The most recent finished last month.
Delivering its judgment on Australia's case against Japan, which saw evidence presented during a three-week hearing last year, the ICJ found Japan's whaling programme in the Antarctic failed to meet the conditions for scientific whaling under regulations set by the International Whaling Commission (IWC), the body charged with the conservation of whales and the regulation of whaling.
It was ruled that no further permits for scientific whaling should be issued under Japan's scientific whaling programme.
In a 12-4 majority judgment, the UN court sided with Australia, finding that Japan's program fell short of following scientific methods, the Associated Press reported.
"The court concludes that the special permits granted by Japan for the killing, taking, and treating of whales ... are not 'for purposes of scientific research'," presiding judge Peter Tomka said.
Attorney-General Chris Finlayson gave evidence on behalf of New Zealand during the court case in the Hague July last year.
He told the court that Japan was wrongly interpreting article eight of the whaling convention, which deals with scientific permit whaling.
"Under Japan's interpretation ... the convention is solely a vehicle for the optimum utilisation of whales through commercial whaling - nothing more than an industry cartel," he said.
Mr McCully said today that the court had ordered Japan to cease whaling under one program but he warned it could try to put together a new program that would meet some of the tests the court had outlined.
"We hope that won't happen and in the short term it won't because this is going to take a bit of working through," Mr McCully told National Radio.
"This judgement ... is very firm and very clear but it still does leave Japan with a decision to make after they've digested this, which is to look at whether they try to devise a new programme that is scientifically based that embark upon whaling in the Southern Ocean again. Our task is to make sure that we carry out a diplomatic conversation that dissuades them from embarking on that course."