TRADE Minister Steven Ciobo has rejected concerns the 12-nation Trans-Pacific Partnership trade deal will fail to pass the Senate or the United States Congress.
Although all nations have signed the deal, it needs to be approved by each country's parliament before it can come into effect.
Hurdles in the United States include Hillary Clinton and Donald Trump being opposed to it and powerful Senate Finance Committee chair Orrin Hatch refusing to endorse it without changes.
Senator Hatch told the ABC on Friday he wanted patents governing biologic medicines to stay in force for 12 years, rather than the five years Australia proposes.
He accused Australian interests of wanting to steal US patents. He doubted Congress would pass the TPP before President Barack Obama left the White House.
But Mr Ciobo, after holding a "very constructive meeting" in Washington with Sen Hatch, said his concerns were part of "an ongoing conversation".
Mr Ciobo said it was "getting close to midnight" in the US to consider the trade deal, and acknowledged there were concerns on this side of the Pacific Ocean, too.
Senator Nick Xenophon and the Greens oppose the deal's current terms and other crossbenchers including Senator-elect Pauline Hanson are likely to oppose it.