Prime Minister Helen Clark and National Party leader John Key said they looked forward to working with Barack Obama, if they won the New Zealand election.
Helen Clark said Mr Obama's election came at a "critical juncture" because of the challenges facing the international environment, including the global financial crisis and global warming.
"New Zealand and the United States have a very long history of friendship and co-operation. We look forward to building on what is already a strong relationship with the United States." She also acknowledged John McCain, commending him on "a hard fought campaign".
National Party leader John Key said it was a "historic" win for Mr Obama. "I look forward, if I am Prime Minister of New Zealand, to having a strong working relationship with him. It is certainly a very historic day for America."
Asked how it would impact on the New Zealand election, he said there was clearly a strong mood for change in the US but it was dangerous to draw too many parallels.
"Whether that will pervade to a strong mood for change in New Zealand we'll only find out on Saturday night.
Here's hoping." Mr Key also said it was important to continue pushing for a free-trade agreement with the United States.
Mr McCain has expressed some support for a free-trade agreement, and Mr Key said although Mr Obama's views were less well known he hoped work would continue. "We are at a strategic disadvantage because Australia has one and we don't ... "
Maori Party co-leader Tariana Turia said she had sent the party's official congratulations to Todd Campbell, the National Rural Vote Director for Barack Obama's campaign team.
"We, in the Maori Party, are greatly buoyed by the energy and enthusiasm shown in the Obama campaign; and have felt uplifted by the magnificent turnout of everyday people, people who are proud to participate in the democratic process."
Green Party co-leader Jeanette Fitzsimons said Obama's victory was an opportunity to take greater action on climate change.
"President-elect Obama aims to cut US greenhouse gas emissions by 80 per cent from 1990 levels by mid-century," she said.
"I look forward to the US playing a role in negotiating a post-Kyoto agreement for international carbon emissions after 2012, and taking steps to reduce its own emissions before that."