Mexico City (AFP) - Mexico will bestow its highest honor for foreign nationals on US President Donald Trump's son-in-law Jared Kushner for his role in saving the country's free-trade agreement with the United States and Canada.

Kushner, an influential White House adviser, will receive the Order of the Aztec Eagle for shepherding the negotiations to reach a new version of the deal, despite Trump's blistering criticism of the original North American Free Trade Agreement (NAFTA).

"Mr Kushner played a fundamental role throughout the process," the Mexican foreign ministry said in a statement.

"His involvement was crucial in beginning the renegotiation of NAFTA, avoiding a unilateral exit by the United States, and his constant and efficient involvement was key in reaching a successful conclusion."

Trump had threatened to axe the 24-year-old NAFTA, calling it the "worst trade deal ever" and a "rip-off" for American workers. But he ultimately agreed to an updated version, dubbed the United States-Mexico-Canada Agreement.

Mexican media reported that President Enrique Pena Nieto would bestow the honor on Kushner, 37, during the G20 summit in Buenos Aires, Argentina this week, where the leaders of all three countries are expected to sign the new deal.

Mexico sends more than 80 percent of its exports to the United States under NAFTA. The foreign ministry called the new deal "a source of stability for the national economy and certainty for millions of Mexican workers."

Past recipients of the Order of the Aztec Eagle include U2 frontman Bono, Hollywood director James Cameron and Microsoft founder Bill Gates.

Kushner, who is married to Trump's daughter Ivanka, has used back-room diplomacy and a close relationship with Mexican Foreign Minister Luis Videgaray to smooth relations between the two neighbors in the face of Trump's sometimes virulent anti-Mexican rhetoric and vows to build a wall on the border.

But the relationship may also have landed Kushner in trouble. He lost his top-level security clearance in February, reportedly after multiple foreign governments -- including Mexico's -- sought to take advantage of his business and political vulnerabilities.