The Government has decided to have its say in the International Court of Justice case Australia has brought against Japanese whaling in the Southern Ocean.
Foreign Minister Murray McCully says the process is called an intervention, which allows a non-party to the case to put its legal views before the court.
He says New Zealand has worked hard with Japan over three years to try to find a permanent solution to whaling in the Southern Ocean and he's "disappointed" the issue now has to be pursued in the International Court of Justice.
"I do not intend to comment any further on our intervention at this stage as the matter is now before the court," he said on Friday.
"The Government will continue to use all avenues possible to try to bring a halt to Japanese whaling in the Southern Ocean."
Australia brought the action before the court in 2010, questioning the validity of Japan's so-called "scientific" whaling programme in the Southern Ocean.
The Government decided in principle in December 2010 to intervene in the case, and this week lodged its intervention.