U.S. President Donald Trump’s latest threat to impose tariffs on auto imports shouldn’t come as a surprise, according to international trade lawyer Mark Warner.

“We did retaliate against the American steel and aluminum tariffs – and we did so outside the framework of the [World Trade Organization], at least initially. We’re also going to complain to the WTO. But we’ve put on these unilateral tariffs,” said Warner, principal at MAAW Law, in an interview with BNN Bloomberg Tuesday.

“So I think it’s predictable that Trump would react.”

Warner’s comments come after the U.S. president threatened to impose auto tariffs in an interview with Fox News Sunday, noting cars are “the big one.”

“You’re going to have an election, it’s going to be very interesting. I have a feeling he’s going to be fine. And the reason is because if they’re not fine, I’m going to tax their cars coming into America, and that’s the big one,” Trump said.

That comment seemed to refer less to the U.S. mid-term elections and more to Mexico’s vote on Sunday that elected Andres Manuel Lopez Obrador as the country’s first leftist leader in decades.                                    

“Obviously the biggest thing [Trump] has to hit us over the head with now is the threat of the auto tariffs,” Warner said. “It’s not immediate, it’s not even clear that he would do it – there’d be a lot of pressure not to do it.”

“It shouldn’t be unexpected that he would respond in some way with some threat.”   

Warner warned if the U.S. were to hit Canada with auto tariffs, it would be “a real kick in the gut” to the country’s economy.

“And that’s why we’ve got to be very careful in how we escalate our response,” he said.  

-With files from Bloomberg News