Trump, Canadian Prime Minister Justin Trudeau and just-departed Mexican president Enrique Peña Nieto signed the NAFTA replacement at a ceremony - during the recent G20 Summit.
National Farmers Union (NFU) said that while USMCA makes important improvements over NAFTA, the deal now does not go far enough to institute a fair trade framework that benefits family farmers and ranchers and restores sovereignty to the US.
President Donald Trump's aggressive trade strategy accelerated on two fronts Monday, with the White House pressing China to quickly follow through on commitments made over the weekend while simultaneously clashing with lawmakers over a fragile North America pact.
And there remains the matter of crippling tariffs on steel and aluminum the Trump administration imposed on imports from Canada, ostensibly for national-security reasons, while the treaty negotiations were on.
Pelosi, who is expected to take the role of House Speaker in January, has repeatedly expressed deep concerns over the deal's enforceability.
Brown gave his take on CNN's "State of the Union" on Sunday.
That would trigger a six-month waiting period before the U.S. could leave the pact - during that time, United States lawmakers would be asked to approve the new deal signed on Friday with America's neighbors. Senate Ag Committee Chair Pat Roberts says the signing marks an important step toward Congress considering the new agreement, which he's looking forward to in the new year.
New North American Trade Pact Signed
Trump praised the deal in the lavish language he uses when touting one of his administration's accomplishments. Trudeau, however, was much more blunt, calling the GM job losses a "heavy blow ".
Some Republicans say they, too, are disinclined to support the agreement in its current form. All those tariffs remain in place despite the signing of the USMCA, much to the displeasure of both Canadian and Mexican governments.
The president also mentioned that he would hold off for a bit at the request of Congress due to President George H.W. Bush's passing.
Robertson expects Donald Trump to finally act on his threat to rescind the NAFTA when he introduces legislation to implement the USMCA to pressure Congress to move on the new agreement within six months.
"I think we will get the support of a lot of Democrats, a very high number of Democrats, absolutely - I have no doubt about it", Lighthizer said. Ms Pelosi described the deal on Friday as a "work in progress" her members could not yet support.
The signing of the trade agreement is largely ceremonial as it will need to be ratified by all three countries before it can formally take effect.
'We (will) get rid of NAFTA, ' he told reporters. As a senator who represents a border state, I will examine this proposed agreement carefully and work to ensure that it actually benefits New Mexico's workers, environment, and border communities as part of a healthy bilateral relationship with Mexico.