Interested in Stock Market?Add Stock Market as an interest to stay up to date on the latest Stock Market news, video, and analysis from ABC News.
"We've got a great economy, but I do think that the uncertainty caused by the volatile tariff situation and this developing trade war could jeopardize that strength and that growth," he said.
Toomey said that while he gives Trump credit for challenging China on some of its trade practices with the U.S., China has not meaningfully changed its behavior. And, because China continues to be a significant part of the American supply chain, tariffs hurt manufacturers at home.
"It's a double-edged sword," he said. "I would have preferred a different set of tactics."
"This Week" Co-Anchor Martha Raddatz spoke with Pennsylvania business owners earlier this week, who said they expect to charge higher prices on consumer goods because of the tariff hikes.
"The consumer ... will see bigger dollars spent or you'll forego a T-shirt, a cap, another item they want to purchase with it," said Greg Baldwin, vice president of merchandising at a Pennsylvania sporting goods store. "They'll have to make choices. But the consumer will absorb it."
However, some consumers who Raddatz spoke with said they think the economy is doing well and will stand behind the president, even if it were to decline.
"I like Trump because he's the non-politician that doesn't spew what people want to hear," said life-long Republican Cathy Wiedmann.
Trump, in response to the criticisms, has maintained that tariffs are having "a devastating effect" on China and will force them to the negotiating table.
"There's nothing you can do but tariffs," he said on a Fox News radio interview Thursday.
Trump has repeatedly asserted it will be China, not American consumers, who will pay for these tariffs. But many U.S. companies said the latest round of import taxes, effective Sunday, means customers will likely see higher prices on goods. The new tariff schedule imposes 15% tariffs on $112 billion in Chinese imports, establishing taxes on 69% of the consumer goods Americans buy from China.
The escalating trade war, the U.S. Chamber of Commerce said, is straining the U.S. economy by raising prices, discouraging investment and creating instability in the market. A growing number of Republicans argue that these costs are too great to justify Trump's trade tactics.
"The uncertainty that we have, the added cost from tariffs, I think they're a threat to growth," Toomey said on Sunday.