President Andrés Manuel López Obrador said on Thursday that he will travel to the border city of Tijuana on Saturday to “defend the dignity of Mexico” in the face of U.S. tariff threats.

“It is an act of unity to defend the dignity of Mexico and in favour of friendship with the people of the United States,” he said of his plans at his daily morning news conference.

U.S. President Donald Trump has threatened to impose 5% tariffs on all Mexican imports as of Monday, unless Mexico acts to stem the surge of Central American migrants to the U.S. border. Negotiators have been meeting in Washington to avert a crisis, but Mr. Trump warned late on Wednesday that “not nearly enough” progress was being made.

The tariffs would be raised by five percent each month until they reach 25 percent, according to Trump, who has brushed off warnings that such a course of action would have major repercussions for both the US and Mexican economy.

Mr. López Obrador told reporters “all options” are under review in the event Mr. Trump goes through with his threat. “But our posture is to preserve, above all, the friendship with the people of the United States,” he said.