Parliament has passed the Bill that allows the Government to ratify the Trans-Pacific Partnership free trade agreement amid opposition complaints that it's a waste of time.
The Bill lines up New Zealand laws with its obligations under the 12-nation agreement which covers 40 percent of global trade and 800 million people.
Partner countries signed it in February but it still has to be ratified - and the United States is the big problem.
President-elect Donald Trump is a vehement opponent and Prime Minister John Key has said the chance of the US Congress ratifying it before the January 20 inauguration is "close to zero".
During the debate on the Bill Labour, the Greens and NZ First said it was a waste of time because the agreement was dead in the water.
Trade Minister Todd McClay said the Bill signalled New Zealand's commitment to international trade liberalisation.
"At times when there is uncertainty in the rest of the world, New Zealand's consistent and trusted voice of negotiating trade outcomes that are good for our economy needs to be heard," he said.
To come into force the TPP must be ratified by at least six countries that account for 85 percent of the group's economic output, meaning the US is essential.
The partner nations are New Zealand, Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, Peru, Singapore, the United States and Vietnam.
The Bill passed its final third reading stage by 61 votes to 57 on Tuesday.
National, ACT and United Future supported it.
Labour, the Greens, NZ First and the Maori Party opposed it.