President Donald Trump, speaking on Tuesday night in Arizona near the Mexican border, said it looks inevitable the U.S. will pull out of the North American Free Trade Agreement. It’s a now familiar threat—but no less concerning given the U.S. just this week wrapped up the first round of negotiations with Mexico and Canada to revise the trade agreement by early next year. Trump’s comment that “we’ll end up probably terminating Nafta at some point” may add to a lurking fear that he won’t have the patience to see the process through. “The danger is that the president either with a very short fuse or his ‘my way or the highway approach”’ will torpedo the talks, Arturo Sarukhan, a former Mexican ambassador to the U.S., said on the sidelines of Nafta talks in Washington. To be sure, it could be a scare tactic. Trump backed down from an earlier threat to scrap the pact after seeing a map of states with Nafta-dependent economies that helped vote him in office. Mexico could have the most to lose if the pact unspools, as the country has been Trump’s prime target. Its foreign minister, Luis Videgaray, said Wednesday that talks are continuing and if Trump really wanted to break up Nafta he would have done so already. Canada expects “moments of heated rhetoric,” during the discussions, its Foreign Ministry said.