WASHINGTON—Ontario Premier Kathleen Wynne says “we’re very worried” about the possibility that U.S. President Donald Trump will impose a tariff on Canadian steel and aluminum.

“It would hurt us,” Wynne said in an interview Saturday in Washington, saying it would “increase the cost of cars.”

Wynne was visiting to promote free trade at a meeting of the National Governors Association. She said her meetings with governors confirmed her belief that the prospects for reaching a North American Free Trade Agreement deal have improved since the fall.

On steel and aluminum, Trump is contemplating a variety of options: a global tariff or global quota, which would hit Canada; a tariff only on specific countries, which would exclude Canada; or a mix of tariffs on some countries and quotas for others.

Trump’s complaint is the “dumping” of low-cost steel from countries such as China. Wynne said Canada is also a victim of dumping.

“To the degree that’s a challenge for the United States, it’s a challenge for Canada. So I think we need to have a North American strategy around dumping steel, and have a partnership on that, as opposed to being in competition with one another,” she said.

On her last visit to Washington, two weeks prior, Wynne announced that Ontario would retaliate against New York state if it did not give the province an exemption from its “Buy American” law that requires certain state agencies to use American-made steel and iron for their projects.

An exemption is unlikely, since the law has already been signed. Wynne said Saturday that she has not heard anything from New York since she issued the threat.