Story highlights Japan research ship heads for Antarctic Ocean for three-month stint

Part of new 12-year program that will kill thousands of minke whales

Japan says deaths are vital to research; critics accuse it of poaching

(CNN) With a mission to kill 333 minke whales, Japan has sent its first whaling fleet to the Antarctic Ocean in more than one year.

The expedition comes despite an International Court of Justice ruling and fierce objections from countries including Australia and New Zealand.

"We do not accept in any way, shape or form the concept of killing whales for so-called 'scientific research," said Australian Environment Minister Greg Hunt.

New Zealand's acting Foreign Minister Todd McClay said: "New Zealand is strongly opposed to whaling in the Southern Ocean. We call on Japan to take heed of the 2014 International Court of Justice decision and international scientific advice concerning their whaling activities."

Japan has consistently rejected calls for its to cease its whaling activities, insisting that it's vital for building a body of research.