The United States, Mexico and Canada signed a new pact to update the 25-year-old North American Free Trade Agreement.

The new agreement, known as USMCA, was signed during an early-morning ceremony Nov. 30 in Buenos Aires, where a Group of 20 summit of advanced and developing economies was being held.

The deal still requires ratification by all three countries. It is expected to pass easily in Canada and Mexico, but faces some opposition in the United States from some Democrats who have expressed reservations about the new agreement.

Democrats in January will take control of the House, where the agreement is expected to have a more difficult path. It is expected to pass more easily in the Senate, where Republicans will retain control in the new Congress.

Acknowledging the often contentious negotiations that led to the signing, President Trump said at the ceremony, "This has been a battle, and battles sometimes make great friendships."

“The new USMCA makes important specific changes that are beneficial to our agricultural producers,"said U.S. Secretary of Agriculture Sonny Perdue. "We have secured greater access to the Mexican and Canadian markets and lowered barriers for many of our products. The deal eliminates Canada’s unfair Class 6 and Class 7 milk pricing schemes, opens additional access to U.S. dairy into Canada, and imposes new disciplines on Canada’s supply management system. The agreement also preserves and expands critical access for U.S. poultry and egg producers and addresses Canada’s discriminatory wheat grading process to help U.S. wheat growers along the border become more competitive."