Australia said Friday it will challenge Japan's whale hunting in the Antarctic at the International Court of Justice, a major legal escalation in its campaign to ban the practice despite Tokyo's insistence on the right to so-called scientific whaling.

Japan's Foreign Ministry called the action regrettable at a time when 88 member-nations of the International Whaling Commission were discussing a proposal that could allow some limited whaling for the first time in 25 years.

"We will continue to explain that the scientific whaling that we are conducting is lawful in accordance with Article 8 of the international convention for the regulation of whaling," said Japan's Foreign Ministry Deputy Press Secretary Hidenobu Sobashima. "If it goes to the court, we are prepared to explain that."

Japan, Norway and Iceland, which harpoon around 2,000 whales annually, argue that many species are abundant enough to continue hunting them. They are backed by around half of the whaling commission's members.

Australia has declared the southern seas a whale sanctuary and has long lobbied for an end to whaling there. The government says Japan's hunt is in breach of international obligations, but has declined to release any details of how it will argue its case before the court in The Hague.

The whaling commission has proposed a plan that would allow hunting without specifying whether it is for commercial or other purposes — but under strict quotas that are lower than the current number of hunted whales.

Commission Chairman Cristian Maquieira expressed optimism Thursday in Washington that the issue could be resolved at a meeting next month in Morocco. But senior U.S. official Monica Medina said the current proposal would allow the hunting of too many whales, signaling difficult negotiations ahead.