President Donald Trump on Monday signed several memoranda that begin rolling back his predecessor’s legacy, including one withdrawing the United States from a massive Asian-Pacific trade pact. It also sets up a conflict with congressional Republicans on policy priorities.

Trump, before taking office, said Monday would be his administration’s first full day of work. His signature essentially makes good on a campaign promise to withdraw from former President Barack Obama’s Trans-Pacific Partnership trade deal “on Day One.” During the campaign, candidate Trump had dubbed the TPP “a potential disaster for our country.”

Seated behind the famed Resolute Desk in the Oval Office, Trump called his move to withdraw from the trade deal a “great thing for the American worker.”

The move immediately pits Trump against some members of his own party, who have long supported free trade.

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Arizona Republican Sen. John McCain said in a statement Monday that the decision to withdraw the U.S. from the TPP is a “serious mistake” that will reduce U.S. sway over trade rules in Asia and U.S. influence in that region, to China’s benefit.

House Speaker Paul D. Ryan issued a statement hailing two other memos Trump signed, but there was no mention of the trade pact. The Wisconsin Republican did, however, applaud Trump for pursuing his pledge to seek “better trade agreements.”

One longtime GOP Trump critic avoided directly taking on the new president on Monday.

“It’s clear that those of us who believe trade is good for American families have done a terrible job defending trade’s historic successes and celebrating its future potential,” Nebraska Sen. Ben Sasse said in a statement. “We have to make the arguments and we have to start now.”

Harry Kazianis, director of defense studies at the Center for the National Interest, said the TPP was always more about assuring Asian allies that America has their back as China rises.

“What happens next will be vital for the Trump administration,” Kazianis said. “President Trump must now find an alternative way to reassure allies in the Asia-Pacific region that Washington will continue to engage the Asia-Pacific. … This could include multiple bilateral trade agreements.”

The TPP decision is not the lone trade-related move the new administration has signaled.

On Sunday, the new president said he will soon meet with the leaders of Canada and Mexico to begin renegotiating the North American Free Trade Agreement and to discuss immigration, including the wall along the southern border he wants to build and have Mexico reimburse the U.S. for.

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Trump also signed a memo on Monday that freezes federal hiring. Notably, he corrected an aide in the Oval Office and pointed out that it exempts the U.S. military.

The move will likely be met with skepticism from lawmakers from both sides of the aisle who hail from states with a large federal footprint, such as Virginia.

Trump also restored a ban on nongovernmental organizations being eligible to receive federal U.S. funds if they perform or counsel women about abortion services or advocate the easing of restrictions on such services in their countries.

“The Trump administration and Republican leadership have made no secret of their dangerous obsession with rolling back reproductive rights,” New Hampshire Democratic Sen. Jeanne Shaheen said in a statement Monday. “President Trump’s reinstatement of the global gag rule ignores decades of research, instead favoring ideological politics over women and families.”

John M. Donnelly contributed to this report.