A US senator has called for the Trans-Pacific Partnership with Australia and other nations to be scrapped and for America to instead use its leverage to strike one-on-one trade deals.

Senator Jeff Sessions also questioned why US President Barack Obama agreed to Auckland as the location for last month's signing of the mega 12-nation Pacific Rim trade deal.

"Obama had this thing signed in Auckland, New Zealand, which claims it is the most remote city in the world," Mr Sessions, speaking at an event at the National Press Club in Washington DC on Thursday, told reporters.

"They didn't even issue a press release on it.

"They're not promoting this."

Mr Sessions, a Republican who has endorsed the party's presidential candidate frontrunner Donald Trump, said it was unlikely the Republican-controlled Congress would vote on the TPP before the November 8 presidential election.

Mr Trump has described the TPP as a "horrible deal".

Mr Obama, at a White House press conference with Canadian Prime Minister Justin Trudeau on Thursday, admitted the US has had "bad trade deals" in the past that served the interests of global corporations instead of workers.

"But I am absolutely persuaded we cannot put up walls around the global economy," Mr Obama said.

The US would be better off if it negotiated individual deals with Pacific Rim nations, Mr Sessions said.

"We should do it bilaterally so if we have a dispute and they want to access the thing they want the most - our market - then we have got leverage," the senator said.

"We can push back a lot better than if we have to go through a 10 or 11-nation commission to vote on it."

Mr Sessions was speaking at the release of a poll conducted by conservative political advocacy group Americans for Limited Government, which found 66 per cent of Republican voters oppose the TPP "after they find out what's in it".

The TPP includes Australia, the US, New Zealand, Canada, Japan, Malaysia, Mexico, Peru, Singapore, Chile, Mexico and Vietnam.