Australia has launched legal action at the International Court of Justice to stop Japan's hunting of whales, Japanese officials said Tuesday, calling the move "extremely regrettable".
Australia's action in The Hague follows months of tension between Canberra and Tokyo, which kills the ocean giants under a loophole in a 1986 international moratorium that allows lethal "scientific research".
"We were informed that Australia has filed a lawsuit with the International Court of Justice regarding research whaling," said a Japanese fisheries agency official. "We will discuss how to deal with it."
Hirofumi Hirano, Japan's top government spokesman, said: "I think it is extremely regrettable. The Japanese government will deal with it properly, based on our position."
Australia has long protested against Japan's annual whaling expeditions in Antarctic waters, and has in recent months hardened its stance, announcing Friday that it would launch legal action in The Hague this week.
"We want to see an end to whales being killed in the name of science in the Southern Ocean," said Environment Protection Minister Peter Garrett last week, vowing "to bring a permanent end to whaling in the Southern Ocean".
A Japanese foreign ministry official told AFP on Tuesday: "We are studying our strategy regarding the lawsuit. Details are yet to be decided, but we won't disclose our strategy even after we make a decision."
The legal action comes just ahead of the June 21-25 annual meeting of the International Whaling Commission in Morocco, which will discuss a compromise proposal to end years of divisions among its pro- and anti-whaling members.
The plan would allow Japan -- as well as Iceland and Norway, which kill whales in defiance of the moratorium -- to hunt the mammals openly if they agree to reduce their catch "significantly" over 10 years.
Australia has attacked the compromise, under which Japan's Antarctic catch would go down to 410 whales next season -- from about 500 this year -- and then 205 in the 2015-2016 season.
Japanese whalers have clashed in recent years with militant environmentalists who harass them on the high seas.
In their annual clashes, the adversaries regularly trade icy jets from water cannon, while the environmentalists hurl blood-red paint containers and rancid butter, or butyric acid, stink bombs at the whaling ships.
The US-based Sea Shepherd Conservation Society harassed Japanese whalers in Antarctic waters for months in the 2009-2010 season, a campaign which both sides say reduced the Japanese cull by several hundred whales.
One of its members, Peter Bethune, is on trial in Japan on five charges after he boarded the security ship of the Japanese whaling fleet in February and was detained.
The New Zealander last week pleaded guilty to all but a charge of assault, which relates to his firing a rancid butter stink-bomb during a February 11 clash with the whalers.
Bethune faces up to 15 years in prison if convicted. His next hearing is set for June 10, when the court will announce the date of the verdict.
Japan, which says whaling has been part of its culture for centuries, is also seeking Interpol's help to arrest Sea Shepherd founder Paul Watson.
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