"In light of the failure of the talks in Morocco to deliver a positive outcome, we will now give consideration to lodging proceedings in the International Court of Justice," McCully said in a statement released by his ministry on Thursday.
"I anticipate a decision on that question will be made quite soon," he said. Australia launched legal proceedings at the ICJ late last month, claiming Japan's "scientific whaling" program is actually commercial whaling in disguise. It accuses Japan of breaching the 1982 moratorium on commercial whaling.
McCully described the collapse of talks between IWC members as "disappointing but not entirely surprising."
"New Zealand is supportive of the suggestion that there should now be a year-long pause in the IWC process. It is crucial that efforts to reach a diplomatic solution are not completely abandoned," he said.
The proposal put forward by the IWC chair and vice chair would have seen the global moratorium on whaling abolished and limited whaling allowed for the next 10 years.
While Japan came to the IWC talks willing to make concessions, "they didn't take us much past the proposed contentious position of the chair and deputy chair that was released some months ago," McCully was quoted by the New Zealand Press Association as saying.
"For us the next big challenge now is to ensure the breakdown of the talks don't mean significant increases in whaling in the southern ocean and I'll be engaging urgently with the Japanese government on that matter," he added.