Barack Obama has scored a major victory in his battle to include the US in the Trans-Pacific Partnership trade pact with Australia, New Zealand and nine other Pacific Rim nations.

The US Senate has voted 60-38 to grant President Obama fast-track authority for the TPP.

The TPP could have been doomed if the Senate refused to give the president fast-track power.

A globalisation commentator believes the signing off the Bill it will only be a matter of weeks before the political trade-offs begin.

Professor Jane Kelsey from the University of Auckland said with America now on board, discussions of the finer points should begin shortly.

"It clears the way for the Ministers now to meet to do some political tradeoffs, probably in two to three weeks time." 

Human Rights Federation spokesman Peter Hosking said this agreement has the potential to affect everyday New Zealanders.

"The government might be able to be sued, for example, for raising the minimum wage via the normal statutory process that we have in New Zealand."