While the 23-year-old North American Free Trade Agreement has come under attack from Republican presidential candidate Donald Trump, the Obama administration said Monday it had brought a new Air Transport Agreement into force with Mexico.

U.S. Transportation Secretary Anthony Foxx said, “This landmark agreement with one of our largest aviation partners will significantly increase future trade and travel between the United States and Mexico. Our success is the result of four years of collaboration with the government of Mexico.”

The agreement will benefit U.S. and Mexican airlines, travelers, businesses, airports and communities, Foxx said, by allowing increased market access for passenger and cargo airlines to fly between any city in Mexico and any city in the U.S.

“Cargo carriers will now have expanded opportunities to provide services that were not available under the more restrictive agreement,” he said. “This new Air Transport Agreement further elevates and strengthens the dynamic commercial and economic relationship between the United States and Mexico, and advances our goal of shared prosperity. This agreement will allow carriers on both sides of the border to better meet increasing demand in our countries, helping to drive economic growth in sectors beyond aviation, including tourism and manufacturing.”

Trump has railed against NAFTA, which also includes Canada, and Mexico in particular, claiming the country takes jobs away from the U.S. and threatening to build a wall at the border to keep out illegal immigrants. He has also said the pending 12-nation Trans-Pacific Partnership should not be ratified, as has Democratic candidate Hillary Clinton.

According to the U.S. Trade Representative’s Office, U.S. exports to Canada and Mexico support more than three million American jobs. As the U.S.’s two largest export markets, Canada and Mexico buy more Made in America goods and services than any other countries in the world, USTR data shows.

The Air Transport Agreement was signed by Foxx and Mexico Secretary of Transport Gerardo Ruiz Esparza on Dec. 18. It went into effect on Monday, but opportunities established by the agreement will become available to U.S. and Mexican airlines on Aug. 21.