Trucks wait in a long queue for border customs control to cross into the U.S. at the Otay Mesa border crossing. REUTERS/Jorge Duenes

The United States, Mexico and Canada are set to begin renegotiation this week of a landmark trade agreement that President Trump once threatened to withdraw from.

U.S. Trade Representative Robert Lighthizer said he will seek “a much better deal” in negotiations over the 23-year-old North American Free Trade Agreement that begin Wednesday in Washington.

“President Trump continues to fulfill his promise to renegotiate NAFTA to get a much better deal for all Americans,” said Lighthizer. “Too many Americans have been hurt by closed factories, exported jobs, and broken political promises. We will seek to address America’s persistent trade imbalances, break down trade barriers, and give Americans new opportunities to grow their exports.”

Most business groups strongly support NAFTA and are wary of the upcoming negotiations. The U.S. Chamber of Commerce said the overriding goal of the negotiations should be to “first, do no harm” to the economy.

“Interrupting the $1.3 trillion in annual trade across our borders or reverting to the high tariffs and other trade barriers that preceded the NAFTA could put at risk many of the 14 million U.S. jobs that depend on trade with Canada and Mexico,” said the chamber, which represents 3 million businesses.

In San Diego, the location of the world’s busiest border crossing, the San Diego Regional Chamber of Commerce has called on local companies to write Lighthizer to express support for the agreement.

“It is critical that we let our federal leadership know how important this agreement is to our region, how it can be improved, and advocate for a continued relationship with Mexico and Canada,” Sanders said in a message to chamber members in June.

Lighthizer said Trump administration’s objectives in the negotiations include adding digital economy rules and strengthening labor and environment obligations. The administration will also work to eliminate unfair subsidies, market-distorting practices by state owned enterprises, and burdensome restrictions on intellectual property.

Mexican officials say they want a deal done by the end of the year, before presidential elections in 2018, when it would be difficult to approve the final agreement.

Chris Jennewein is founder and senior editor of Times of San Diego.