BISMARCK, N.D. — U.S. Sen. Heidi Heitkamp says President Donald Trump’s proposed tariffs on steel and aluminum imports threaten North Dakota’s economy.

Rep. Kevin Cramer, facing Heitkamp in a Senate race expected to be one of the nation’s toughest, doesn’t appear to like them either.

Trump’s pledge to impose the tariffs has escalated tensions with China, Europe and other trading partners. It’s also raised concern in his own party.

Heitkamp, a Democrat, says China and Europe are important markets for machinery and agriculture exports.

Cramer, a Republican, says he doesn’t like tariffs in general and he worries about retaliation from U.S. trading partners. He says he hopes Trump is just trying a negotiating tactic.

GOP Sen. John Hoeven says trade policy changes should not lead to retaliation that could hurt U.S. interests.