WASHINGTON—House Democrats have reached an agreement with the White House to strengthen labor, environmental, pharmaceutical and enforcement provisions in President Trump’s North American trade pact, a significant development that moves the president’s signature trade deal closer to becoming law.

The decision to proceed with the United States-Mexico-Canada-Agreement (USMCA) came after Democrats said they secured concessions from the White House to strengthen provisions in a trade pact that governs commerce across North America. Those changes were critical to winning the support of labor unions, including the powerful AFL-CIO.

The changes to USMCA, which the three countries signed more than a year ago, must now be woven into implementing legislation that the House and Senate will both vote on. The pact will also need to secure the president’s signature and the final approval of the Mexican senate and Canadian leadership.

At a news conference on Tuesday, Pelosi said she was confident that the legislation would become law, replacing the much-maligned North American Free Trade Agreement and fulfilling a legislative priority for both the administration and the House Democratic caucus.

“Manufacturers support the USMCA, and we are encouraged that the administration and House Democrats have forged a path forward, with the support of Canada and Mexico as well,” says Jay Timmons, president of the National Association of Manufacturers. “As with any agreement of this nature, not every objective that we sought was met. For instance, we are extremely disappointed that the agreement missed an opportunity to set the gold standard for the protection of American-made life-saving innovations and inventions. Protection of intellectual property is a key principle and critical for the long-term vitality of the manufacturing industry and the men and women who work in our sector.”