"We have chose to withdraw from the International Whaling Commission in order to resume commercial whaling in July next year", Yoshihide Suga, top spokesperson for the Japanese government, told reporters.
Japan announced on December 26 that it will leave the International Whaling Commission (IWC) at the end of June and resume commercial whaling in July for the first time in about 30 years.
Japan chose to withdraw from the organization since its calls for the whaling resumption due to the growing number of whales had not been supported by other states in the IWC, the NHK World broadcaster reported.
Mr Suga said the IWC has been overlooked by conservationists and Japan was frustrated over its attempts to manage whale capitals even though the IWC has a treaty mandate for both whale conservation and development of the whaling industry.
The government's top spokesman referred to a recent IWC meeting that had rejected Japan's proposal to allow for a resumption of commercial whaling and organizational reforms.
The research programme was criticised as being a cover for commercial hunting.
Mr Suga said Japan will notify the IWC of its decision by 31 December and remains committed to global cooperation on proper management of marine living resources even after its IWC withdrawal.
"But if we don't explain internationally that whales are increasing. people won't understand", she added.
The IWC imposed a commercial moratorium in 1986 due to a dwindling whale population, which Japan was a part of.
The announcement had been widely expected and comes after Japan failed in a bid earlier this year to convince the IWC to allow it to resume commercial whaling.
"The next great thing about it is that if they leave the IWC, that means the Atlantic whale sanctuary will then go ahead because they've been voting against that for years".
Japan slashed its annual quota in the Antarctic by about one third after a 2014 International Court of Justice ruling that the country's research whaling program wasn't as scientific as Japan had argued.
It will also cease whaling activities in the Antarctic Ocean, according to an official statement released Wednesday, and hunt species with so-called "healthy" population numbers.
The Japanese government, under pressure from the local fishing industry, has decided it could not restart commercial whaling while being a member of the global body responsible for the conservation of whales.
Japan has hunted whales for centuries, and their meat was a key source of protein in the immediate post-World War II years when the country was desperately poor.
Suga said Japan will notify the IWC of its decision by December 31 and remains committed to worldwide co-operation on proper management of marine living resources even after its IWC withdrawal.
Many members of Prime Minister Shinzo Abe's Liberal Democratic Party do support whaling, and he himself comes from a constituency where whale hunting remains popular.
By the way, today's announcement doesn't mean that Japan hasn't been hunting whales all this time.
It makes no secret however of the fact that meat from the expeditions ends up on dinner tables.