The Prime Minister is arguing there will be economic as well as political benefits if New Zealand wins a place on the United Nations Security Council in 2015-16.
John Key is in New York for the UN General Assembly and is spending most of his time lobbying other leaders to support New Zealand's bid to get on the Security Council.
Mr Key says being on the council would enable New Zealand to have a much wider range of contacts with other countries.
He says it would give this country a greater voice in world affairs and there would also be economic benefits.
"Think about a continent like Africa - today, as it stands, New Zealand doesn't have a deep relationship on that continent. But in 10 or 20 or 30 years time ... it will be a very powerful trading force, buying a lot of products that might come out of New Zealand," he says.
Mr Key will not put a cost on what New Zealand's campaign is costing but says it is worth it.
He says New Zealand is not spending as much as its two competitors, Turkey and Spain.
However, Mr Key says the Government is still spending millions of dollars, including offering aid to potential supporters.
He says New Zealand is using agricultural diplomacy to help its campaign. For instance, he was due on Thursday to meet the Prime Minister of Lesotho, a country which depends heavily on agriculture.
But New Zealand is likely to provide aid to Lesotho anyway, says Mr Key.
Mr Key says he hopes countries which receive New Zealand aid will support its bid, but Spain and Turkey are also giving aid to many of the same countries and their budgets are much greater.
The election will be held a year from now and countries need at least 129 votes from the 193 General Assembly members to win a spot on the Security Council.
Meanwhile, Mr Key met at the United Nations with Colombian President Juan Manuel Santos Calderon and discussed a potential free trade agreement between the two countries.
The prospect of a deal was first raised when Mr Key visited Colombia earlier in the year.
Mr Key says preliminary work on starting negotiations is already underway and officials have done an early scoping study.
He says there are a few issues that need to be worked through before launching any formal negotiation.