(CNN) -- Australia is asking an international court to weigh in on Japan's whale-hunting practices, officials said Tuesday.
Japanese officials say their hunts are permitted under rules prohibit commercial whaling but allow whaling for scientific reasons.
But Australian officials said they've filed a lawsuit with the International Court of Justice in The Hague, Netherlands, to stop Japan from exploiting the research loophole.
"We believe that it's possible to do all the research that you need to do and understand everything that you need to ... and you don't have to kill them to do it," Australian Environment Minister Peter Garrett told CNN Tuesday.
Japanese Foreign Ministry spokesman Hidenobu Sobashima said Tuesday that Japan's whaling, which has killed up to 1,000 whales in Antarctic waters annually, is authorized.
"Japan's research whaling is a legal activity," he said, noting that the country would continue to explain its perspective in international court.
The move toward legal action is "regrettable," Sobashima said, when international whale-hunting rules are still being negotiated.
The International Whaling Commission is scheduled to evaluate existing whaling rules at its annual meeting in June.
But Garrett said diplomatic negotiations over the issues have not produced results. He stressed that taking the case to court does not mean that the relationship between Australia and Japan -- strong allies and trading partners -- has soured.
"We think we can disagree about one thing and continue to have close relationships across a range of other issues," he said.
Japan's whaling has drawn sharp criticism from environmental advocacy groups, who claim it involves the cruel slaughter of whales so that meat can be sold in markets and restaurants.
Japan's fisheries agency has said that it wants "sustainable whaling" and also advocates conservation.
"Clearly, the acceptance of other cultures' dietary practices and the promotion of cultural diversity is as important as saving endangered species and the promotion of biological diversity," the agency's website says. "If the consumption of whale meat does not endanger whale species, those who find the practice unacceptable for themselves should not try to impose their view on others."
Australia's lawsuit comes as an anti-whaling activist was facing charges including assault and trespassing in a Japanese court.
Prosecutors allege that Peter Bethune, an environmental activist from New Zealand, threw butyric acid at a whaling ship, jumped aboard and attempted to make a citizen's arrest of the captain.
Bethune has pleaded guilty to all charges accept assault. He testified Monday that he did not intend to hurt anyone. A verdict is expected later this month.
CNN's Yoko Wakatsuki contributed to this report.