Japan's chief whaling negotiator confirmed Monday its ships would return to the Antarctic this year, despite a call by global regulators to provide more evidence that the hunt has a scientific purpose.

Joji Morishita said the whole debate about whether or not Japan should be killing the mammals had long since moved away from science and into politics.

The scientific committee of the International Whaling Commission said Friday that Japan had failed to give enough detail to explain why it wanted to kill almost 4,000 minke whales in the Antarctic over the next 12 years.

Despite international disapproval, Japan has hunted whales in the Southern Ocean under an exemption in the global whaling moratorium that allows for lethal research.

It makes no secret of the fact that meat from the mammals -- killed ostensibly for research -- is processed into food, and says the whale population in any case is big enough to allow sustainable whaling.

"There is no definite conclusion in the report itself... which is not so surprising in the IWC, because as we know very well the IWC is a divided organisation," Morishita told reporters.

"Because of this division, even the scientific committee is always having difficulty of coming up with some kind of a conclusion.

"Still... we will try to provide as much scientific research as possible and try to get" approval from the scientific committee for their go-ahead.

"But this could be a never-ending story. Well this has been a never-ending story," Morishita added.

Asked whether Japanese ships would hunt in the Southern Ocean later this year, he said Tokyo's position had not changed since an announcement on Friday.

Japan does not need permission from the IWC to press on with its "lethal sampling" hunt in December, as it is ultimately up to individual countries to issue permits for whaling on scientific grounds.

However, Tokyo is always keen to appear to be complying with international rules.

Japan believes the world's whale population, especially the minke stock, is sizeable enough to accommodate a return to sustainable whaling, putting it at odds with campaigners and anti-whaling nations.

It accuses opponents of being emotional about whales and disregarding what it says is evidence to support its position.

Last year, the highest court of the United Nations, the International Court of Justice, ruled that the annual Southern Ocean expedition was a commercial hunt masquerading as science to skirt the international moratorium.

Morishita said regardless of whether or not there was a market for whalemeat in Japan, the principle of hunting whales was important because banning the killing of one animal instead of another was "strange logic".

"If you keep on like this, I worry that a country which has international political power could impose its standards and ethics on others," he said, calling it "environmental imperialism".

"For example, if India becomes the world's number one power and starts to say 'Don't eat beef', what shall we do?"