Japan said Friday it would redesign its controversial Antarctic whaling mission in a bid to make it more scientific, after a United Nations court ruled it was a commercial hunt masquerading as research.

The bullish response, which could see harpoon ships back in the Southern Ocean next year, sets Tokyo back on a collision course with environmentalists.

Campaigners had hailed the decision by the International Court of Justice, with hopes that it might herald the end of a practice they view as barbaric.

"We will carry out extensive studies in cooperation with ministries concerned to submit a new research programme by this autumn to the International Whaling Commission (IWC), reflecting the criteria laid out in the verdict," said Yoshimasa Hayashi, minister of agriculture, forestry and fisheries.

Japan, a member of the IWC, has hunted whales under a loophole allowing for lethal research. It has always maintained that it was intending to prove the whale population was large enough to sustain commercial hunting.

But it never hid the fact that the by-product of whale meat made its way onto menus.

"The verdict confirmed that the (IWC moratorium) is partly aimed at sustainable use of whale resources.

"Following this, our country will firmly maintain its basic policy of conducting whaling for research, on the basis of international law and scientific foundations, to collect scientific data necessary for the regulation of whale resources, and aim for resumption of commercial whaling."

Hayashi, who had met with Japanese Prime Minister Shinzo Abe earlier in the day, confirmed a previous announcement that the 2014-15 hunt in the Southern Ocean would not go ahead.

Last month's court ruling does not apply to Japan's two other whaling programmes: a "research" hunt in coastal waters and in the northwestern Pacific, and a much smaller programme that operates along the coast, which is not subject to the international ban.

- Pacific hunt 'scaled back' -

Hayashi said the northwestern Pacific hunt, which is due to depart Japanese shores on April 26, would continue, albeit in a slightly reduced form.

A statement released by the fisheries agency said the hunt would be scaled back, and was aiming to net around 100 minke whales in coastal waters, down from 120 last year, and 110 other whales offshore, down from 160. No minke whales would be caught in the deep ocean.

An element of the court's ruling was that the Japanese mission was catching far too many whales for it to be considered legitimate scientific research.

Some commentators had suggested that Tokyo might use the court decision as cover to retreat from an entrenched position in which it defended as vital cultural heritage a practice that costs a lot of taxpayers' money and does not enjoy much public support.

Friday's announcement will come as a blow to anti-whaling campaigners, who had urged Tokyo to follow the spirit of the court ruling and heed global public opinion, which they say is firmly against hunting whales.

"This announcement is a huge disappointment and flies in the face of the UN's International Court of Justice ruling last month," said Greenpeace Japan executive Director Junichi Sato, adding that the decision was bound to "damage Japan's international standing".

"The continued commercial hunting of whales, supposedly for research purposes will surely be challenged legally, especially when endangered species are still being targeted," Sato said in a statement.

Environmental activist group Sea Shepherd, whose sometimes aggressive confrontations with Japanese whaling boats on the high seas saw them labelled "pirates" by a US judge, said earlier this month they expected Tokyo to try to work around the court ruling.

Hayashi said Friday that Tokyo would redouble its efforts to foil potential saboteurs who have trailed their fleets around the Southern Ocean for several years.

"As for unlawful acts of violence committed by anti-whaling organisations, we will study counter-measures in line with a new research programme from the standpoint of ensuring the safety of the research fleet, researchers and crew members," he said.