WASHINGTON — Sen. Pat Toomey, R-Pa., warned his fellow Republicans Sunday that the bipartisan replacement to the North American Free Trade Agreement represents a step back in America's trade policy.

In an appearance on "Meet the Press," Toomey said that the agreement between President Donald Trump and House Democrats on the trade deal for the United States, Mexico and Canada (USMCA), represented a departure from free-trade principles.

“I think the president is mistaken on this," he said of Trump's concerns about America's trade deficit with Mexico.

"USMCA is an exercise, through all types of new provisions, to diminish trade — and that’s why I hope Republicans will reconsider this. We've historically recognized that we are all better off with more open markets.”

Trump has made the USMCA a central priority for his administration, and Democrats last week announced they had reached a deal with the administration to pass it.

Last week, before the announced agreement, Trump tweeted the trade deal would be the "best and most important trade deal ever made by the USA."

Trump and leaders from Canada and Mexico signed the deal last year, agreeing to modernize the decades-old agreement with a new deal on issues like dairy trade and tariff relief, as well as reimagining the deal to address newer technology that wasn't considered when the previous deal was negotiated in the 1990s.

But Congress has to ratify the deal, and Democrats immediately raised concerns about the plan. They ultimately won concessions with the administration in areas like workers' protections.

Toomey, one of the few Republican dissenters to the deal, called the outcome of those Congressional negotiations a "complete capitulation" to House Speaker Nancy Pelosi, D-Calif., and Richard Trumka, the president of the powerful AFL-CIO federation of labor unions.