New Zealand is vowing to continue its fight to turn Antarctica's Ross Sea into the world's largest marine protected area, despite its proposal being blocked for a third time.

Photo: RNZ

New Zealand and the United States want 1.3 million square kilometres of the ocean to be protected, with only a small amount of fishing allowed in that area.

The countries failed to convince the other 23 members of the Commission for the Conservation of Antarctic Marine Living Resources meeting in Hobart, Australia, to agree to it.

Despite negotiations going into the early hours of Friday morning, a consensus could not be reached.

Russia blocked the deal, with support from Ukraine, due to concerns about the size of the reserve and fishing restrictions.

One of Ukraine's delegates told Radio New Zealand outside the talks that the plan needs more work. He says it should be investigated further and there needs to be more research.

New Zealand's head negotiator Carolyn Schwalger said on Friday the Government has made it clear it wants the reserve to go ahead, so it will attempt for a fourth time to convince other nations.

"It will never be the end, I don't think. The Government has said very clearly we're committed to this initiative, it's too important.

"Of course, we'll have to go back and regroup and think about what our next steps are. I'll have a discussion with the minister when I get home, but I'm sure we're committed to the fight."

Ms Schwalger said the New Zealand team will regroup with the US and see if anything needs to be changed before lobbying continues ahead of the next meeting, expected to be in October 2014.

Environmental groups holding signs with sad faces protested outside the commission's building in Tasmania following the decision.