Opening the meeting Minoru Morimoto, the commissioner for Japan, said his country wanted to improve dialogue over whaling but said the IWC was in need of reform.
He said the atmosphere between pro- and anti-whaling nations at the IWC had "become one of confrontation".
His comments came as conservationists pursuing the Japanese whaling fleet off Antarctica threatened to physically ram Japanese whalers to stop the hunt.
Japan's Fisheries Agency organised the Tokyo meeting outside the framework of the IWC as part of its campaign to resume commercial whaling.
|Whale meat is sold in some Japanese |
restaurants and supermarkets [Reuters]
It has urged the IWC to seriously consider resuming commercial hunting, which was banned in 1986.
Anti-whaling protesters held a demonstration outside the meeting in Tokyo, one of them dressed as a weeping whale.
Junichi Sato, chief campaigner for Greenpeace Japan, said: "Many countries in the IWC agree that it needs to be reformed but not in the way that Japan has presented."
He said Japan was "recruiting countries with money", charges Japan has denied.
Japan says that whaling is a cherished cultural tradition and argues that whale stocks have sufficiently recovered since 1986 to allow a resumption of limited hunts of certain species.
At present Japanese whalers catch more than 1,000 whales each year under clause in the moratorium that allows whaling for scientific research purposes.
The meat, which under IWC rules must be sold for consumption, ends up in supermarkets and pricey restaurants.
On Monday, a Japanese whaling ship and protest vessels with the Sea Shepherd conservation group collided in the Antarctic Ocean.
Both sides have accused the other of causing the collision, the second such clash since last week.
Sea Shepherd ships surround Japanese whaling
ship Kaiko Maru (centre) [Reuters]
Sea Shepherd’s self-stated aim is to "harass, block, obstruct, and intervene against" Japanese ships hunting whales in Antarctic waters.
Paul Watson, the founder of Sea Shepherd, and who is on board the group's Farley Mowat ship, has threatened in media interviews this week to ram Japanese whale boats.
Both Sea Shepherd and Japanese officials claimed to have been rammed by the other's vessel, leaving the protest vessel Robert Hunter with a one-meter gash in its stern above the water line.
Japan has condemned the tactics as sea piracy while officials in New Zealand have warned that confrontations were putting lives at risk.
On Tuesday Chris Carter, New Zealand's conservation minister, rebuked both the Japanese whalers and anti-whaling protesters for what he called their "stupid playground behaviour".
"Sea Shepherd's protest has gone too far," he said, adding that continuing such action risked "severe damage to the cause of whale conservation".