Mexico’s ambassador to Canada said that Mexico will not “overreact†to U.S. President Donald Trump’s new threat to slap tariffs on Mexican goods unless it cracks down on the flow of migrants at the U.S.-Mexico border, but called the pledge “very bad†for the new North American free-trade agreement.

In an interview with CTV’s Power Play on Friday, Juan Jose Gomez Camacho, Mexico’s relatively new envoy to Canada, said that Mexico “got surprised, as everybody else†by the threat from the White House on Thursday night.

Trump warned in a series of tweets that he would begin imposing escalating tariffs on all imports to the U.S. from Mexico beginning next month

The timing of the president’s alert caught many off guard.

It came just hours after U.S. Vice-President Mike Pence and Prime Minister Justin Trudeau met in Ottawa in an effort to build momentum to pass the deal, which was signed last year. They also came nearly two weeks after Canada and the U.S. reached an agreement to lift steel and aluminum tariffs – a major impediment to the deal’s ratification.

Lawmakers in all three countries must approve the pact before it can go into force.

“This is unexpected. This is unwanted. This is a major challenge,†said Gomez Camacho.

He added that Mexican President Manuel Lopez Obrador sent Trump a “very assertive†letter that emphasized the importance of dialogue between their two countries, explained how Mexico has been working to curb migration flows and argued that tariffs are the wrong tool to use to address the issue.

“Tariffs across the board hurt us all,†Gomez Camacho said.

Mexico’s foreign minister and a delegation of other officials will be heading to Washington, D.C., next week, he said, to meet with their American counterparts.

“What we need instead of being pressured by the U.S. is working with the U.S. to address this challenge,†Gomez Camacho said, adding that the two countries need to find “common understanding.â€

Canada introduced legislation earlier this week to ratify the deal before Parliament rises in June, and Mexico’s Senate received the agreement for study on Thursday.

Despite the “challenge†posed by the threat, Gomez Camacho said that Mexico’s government will continue its efforts to pass the agreement and that he still believes Trump wants the agreement to go through, too.

“We are neighbours,†he said. “We are there and we will stay there.â€