Japan's moves to restart Antarctic whaling cause deep concern for the government.

Japan's seeking international support for a revised scientific whaling programme, which it expects to put before the International Whaling Commission later this year.

Prime Minister John Key says that's unacceptable.

"I'd be deeply disappointed. New Zealand was part of the legal case that was taken to the International Court of Justice. The message from the ICJ was very clear, and in my opinion the message to Japan should be very clear."