In a joint press conference with Australian Prime Minister Julia Gillard, Mr Key said both nations had a strong history of working together, dating back to the Anzacs.
He said both nations could maximise from the boom in the Asian economies by marketing Australia and New Zealand together.
"When Australia does well, New Zealand does well," Mr Key told reporters in Melbourne today.
"It's plain for everyone to see the strength that's emerging in the Asia region.
"That's not just China, it's a very powerful seismic shift.
"That presents a lot of opportunities, I think, to both Australia and New Zealand.
"There are some real opportunities, I think, for us to market New Zealand and Australia together and to do some things together."
He thanked the Australian government for the help and resources that were provided to New Zealand during last year's earthquakes in Christchurch and the Pike River Mine disaster.
Ms Gillard said the relationship between both nations was one of family.
"We saw that on display last year when we were both in times of need," said Ms Gillard.
Ms Gillard said ministers from both governments had discussed the future of the transtasman relationship, streamlining defence collaboration, and the global economic climate and the challenges it posed for both nations.
"We've talked about the strength of our region and the fact that we are both situated in the region of the world that continues to experience economic growth and will during the course of this century," she said.
"That gives us particular opportunities for the future."
Ms Gillard said the Australian and New Zealand productivity commissions would work together on a joint study on how the nations could build on their economic ties.
She also announced the establishment of an Australian-New Zealand cyber dialogue to deal with the challenge of cyber security.
"We've got work to do in our region, we've got work to do in Afghanistan, work to do in formats like the East Asia Summit and APEC and work to do directly together," Ms Gillard said.
