New Zealand will not join Australian legal action against Japan over Southern Ocean whaling until diplomatic avenues are exhausted, Prime Minister John Key says. Australia said yesterday it would initiate the action in the International Court of Justice in The Hague next week.

The decision comes five months ahead of a deadline Australia set to determine an agreement with Japan over Southern Ocean whaling. New Zealand's position has been to try to make progress through the International Whaling Commission and Mr Key said he believed diplomacy offered the best chance of a reduction and the elimination of whaling.