Sen. John Curtis (R-Utah) was not among the few Republican lawmakers who rebuked President Donald Trump over his emergency tariffs on Canada earlier this year, but nonetheless he delivered a warning over the weekend about the potentially devastating consequences of the president’s tariff policies.

The GOP senator sat down with CNN’s Manu Raju for a wide-ranging discussion Sunday about the current state of the Republican Party, and when asked about which of Trump’s many controversial actions has caused him the most concern, Curtis spoke plainly.

“If we’re not careful, we’ll destroy small businesses with tariffs,” he told the “Inside Politics Sunday” host. “And I understand, you have to play the long game with President Trump and tariffs, and I’m not one to step in and out-guess his negotiating style or technique.”

“But I do think we have to be very, very careful with our small businesses, particularly when it comes to these tariffs,” continued Curtis, who had just finished giving a speech on the Senate floor about the need for greater transparency in government.

Trump announced a sweeping 10% baseline tariff last month on almost all imports to the U.S., with levies on China set even higher. While the president argues this could revive American manufacturing, economists have warned of a potential recession, or worse.