The Government has summoned Japan's ambassador to the Ministry of Foreign Affairs for a reprimand after whalers entered New Zealand waters.
Last week, a ship involved in security for Japan's whaling fleet followed a vessel belonging to conservation group Sea Shepherd into New Zealand's exclusive economic zone in the Southern Ocean, despite the New Zealand embassy in Tokyo saying that was unacceptable. The ship did stay outside the country's territorial waters.
The Government said the ambassador was called to the ministry on Monday afternoon where a senior official expressed its disappointment at the whalers' entry.
Prime Minister John Key told reporters New Zealand has expressed its deep displeasure both here and in Tokyo. He said overall, New Zealand has an good relationship with Japan, but is strongly opposed to whaling in the Southern Ocean.
Mr Key says the Government could take further action, but won't speculate on what that might be.
New Zealand cannot prevent vessels from entering the exclusive economic zone - set at 200 nautical miles from the territorial mark - but does have some leverage to exclude vessels from its territorial waters.
Foreign Affairs Minister Murray McCully said when embassy staff in Tokyo were advised the Shonan Maru No. 2 might follow the protest ship Steve Irwin into the economic zone, they made it clear this was not acceptable.
Mr McCully told Radio New Zealand's Morning Report programme on Monday while the Japanese decision to ignore New Zealand's wishes has no legal implications, it was unhelpful, disrespectful and short-sighted.
"There are other exchanges that take place between our two foreign ministries and ministers, and we'll just think about the best way in which we can convey the message forcefully, and try and ensure that Japan understands that these things are deeply annoying to New Zealanders and that the relationship is not going to be helped by this sort of thing."
Sea Shepherd said it was pleased to see that the New Zealand Government was finally taking action against the Japanese whalers. Bruce Hawkins, a warrant officer the Steve Irwin said Mr McCully's action was certainly helpful.
"We have watched the trend of governments, both Australia and New Zealand, starting to listen to their constituents, their public, who are outraged. And it's really good to see the government is finally starting to heed this, and you know, take actions which they can take quite reasonably."
A spokesperson for the whalers, Glenn Inwood of the Institute for Cetacean Research, said none of the vessels' moves are done without Japanese government sanction and all ships have a legal right of access to exclusive economic zones.
"None of the moves that are being made by the Japanese vessels are done without the approval of the Japanese government.
"Some of vessels themselves are run by (the) fisheries agency and have Japanese coastguard on board and Japanese police ... This is a whole-of-government operation from the Japanese end."