Japan's determined bid to return to commercial whale hunting was rejected by the International Whaling Commission (IWC) Friday in a tense vote that left the 72-year old organization at a crossroads.

Japan's vice-minister for fisheries Masaaki Taniai said he "regretted" the vote's outcome, and threatened Tokyo's withdrawal from the 89-member body if progress could not be made towards a return to commercial whaling.

"If scientific evidence and diversity is not respected, if commercial whaling is completely denied... Japan will be pressed to undertake a fundamental reassessment of its position as a member of the IWC," he said.

Japan's IWC commissioner Joji Morishita declined to comment when asked if this would be Japan's last appearance at the IWC, an organization which he has chaired for the past two years. His term ended Friday.

Minutes after the meeting he told AFP that differences with anti-whaling nations were "very clear" and Japan would now plan it's "next steps".

Anti-whaling nations led by Australia, the European Union and the United States, defeated Japan's "Way Forward" proposal in a 41 to 27 vote.

Japan had sought consensus for its plan but had been forced to push the proposal to a vote "to demonstrate the resounding voices of support" for a return to sustainable whaling for profit, said Taniai.

Pacific and Caribbean island nations as well as Nicaragua and several African countries, including Morocco, Kenya and Tanzania, voted with Japan, as did Asian nations Laos and Cambodia. Korea abstained.

- 'Sharp split' -

The Russian Federation, which like several states allows IWC-monitored aboriginal subsistence whaling, said it abstained because it did not want to exacerbate an already "deep split within the commission".

The body's identity crisis was clear in a week of often robust exchanges between pro- and anti-whaling nations.

Morishita told AFP a decision lay ahead over whether whaling could be managed in the future by "a different organization or a combination of different organizations?"

The large Japanese delegation here would "assess the result of this meeting very carefully back in Japan," said Morishita.

The IWC was set up in 1946 to conserve and manage the world's whale and cetacean population. It introduced a moratorium on commercial whaling in 1986 after some species had been fished to near extinction.

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Japan insists whale stocks have sufficiently recovered to allow commercial hunting to resume.

Tokyo currently observes the moratorium but exploits a loophole to kill hundreds of whales every year for "scientific purposes" as well as to sell the meat.

Norway and Iceland ignore the moratorium and are key supporters of Japan's bid to resume commercial whaling.

A Japanese withdrawal would have far-reaching consequences for the organization, given support from a growing number of developing states in the IWC.

They say the IWC's mandate is both to conserve and manage -- meaning to sustainably hunt -- recovering whale stocks, but that the emphasis within the organization has leant too far towards conservation, leaving pro-whaling nations without a voice.

To add insult to injury from Japan's point of view, the IWC adopted Brazil's "Florianopolis Declaration" which envisages whale protection in perpetuity.

However much that agreement is non-binding, anti-whaling states championed it as an important indicator of the IWC's future direction.

Taniai said the result of the vote on the Japanese proposal was a "denial of the possibility for governments with different views to coexist with mutual understanding and respect within the IWC."

Australia's commissioner Nick Gales rejected "the narrative of underlying dysfunction and intolerance" suggested by Japan.

He urged Tokyo to remain in the organization "to continue to argue for its view and work constructively with all members."

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- Way Forward or Way Out -

Japan's "Way Forward" included the establishment of a "Sustainable Whaling Committee" within the IWC, and a conference to amend the body's voting rules, changing them from requiring a two-thirds majority to a simple majority.

Anti-whaling NGOs cheered the result, but it seems clear from the week-long meeting in the surfing resort of Florianopolis that Japan's impatience with its fellow members is growing.

Kitty Block, head of the animal charity Humane Society International, said "the IWC's moral compass" had led it to reject Japan's proposal.

"It's clear from exchanges this week that those countries here fighting for the protection of whales are not prepared to have the IWC's progressive conservation agenda held hostage to Japan's unreasonable whaling demands."

Glenn Inwood, of Opes Oceani, a company that analyzes developments in the use of ocean resources, says there is no longer much of an economic or political case for Japan remaining in the body.

"Japan invests tens of millions of dollars each year into its whaling activities but gains very little from the IWC despite being its biggest benefactor," said Inwood, a former spokesman for the Japanese delegation.