Treasury Secretary Janet Yellen is set to warn that proposals for sweeping tariffs are “deeply misguided,” would ramp up inflation and hurt American businesses, offering a clear critique of former President Donald Trump’s economic policy.

Yellen is set to deliver the warning during a speech at the Council on Foreign Relations in New York City on Thursday afternoon and comes as economic issues remain a top concern for voters with the election just under three weeks away. Trump has made his call for steep tariffs a key piece of his policy agenda, while Vice President Kamala Harris has warned his tariff plans would raises prices for American families, referring to it as a “Trump tax.”

Though she is not expected to mention Trump by name, Yellen, who typically refrains from wading into politics, will argue against across-the-board tariffs and a “go it alone” strategy on the global stage.

“Calls for walling America off with high tariffs on friends and competitors alike or by treating even our closest allies as transactional partners are deeply misguided,” Yellen will say, according to excerpts released by the Treasury Department. “Sweeping, untargeted tariffs would raise prices for American families and make our businesses less competitive.”

“And we cannot even hope to advance our economic and security interests — such as opposing Russia’s illegal invasion of Ukraine — if we go it alone,” she will say. “But the issues we face today, from broken supply chains, to climate change and global pandemic preparedness, to China’s industrial overcapacity, also mean we cannot simply draw from an old playbook.”

Trump implemented sweeping tariffs on about $300 billion of Chinese-made products while in office. The Biden administration kept those tariffs in place and in some cases expanded upon them.

Trump has said that, if elected, he would impose tariffs of up to 20% on every foreign import coming into the US as well as another tariff upward of 60% on all Chinese imports. He’s also said he would implement a “100% tariff” on countries that shift away from using the US dollar.

“To me, the most beautiful word in the dictionary is tariff,” Trump said at the Economic Club of Chicago on Tuesday.

Trump defended his calls for tariffs when pressed about the negative impacts by Bloomberg News Editor-in-Chief John Micklethwait, who said it was “just simple mathematics” that the tariffs would pass on higher costs to American consumers.

“Number one, it’s for the protection that we have here and the new companies that will move in because we’re going to have thousand of companies moving into this country,” said Trump, who argued tariffs would have a “positive, not a negative” effect on the economy.

CNN’s Jordan Valinsky contributed to this report.