In an interview on NBC’s Meet the Press that aired Sunday, he was asked if he could guarantee that American families won’t pay more.

“I can’t guarantee anything,” Trump replied. “I can’t guarantee tomorrow.”

On the campaign trail, he vowed to impose tariffs as high as 20% across the board while singling out China with duties of up to 60%. After winning the election last month, he later threatened that one of his first executive orders would be a 25% tariff on Canada and Mexico if they didn’t curb illegal immigration and drug trafficking, plus an additional 10% tariff on China.

Companies pay tariffs and typically pass on at least part of the additional cost to consumers. Top CEOs have already warned that tariffs would translate to price hikes. And this past week, Dollar Tree said tariffs might force the deep-discount chain to increase prices and stop selling some products entirely.

Meanwhile, U.S. businesses that rely on imports have been stockpiling key goods to get ahead of Trump’s tariffs as much as possible.

But Trump told NBC that the tariffs he imposed during his first term, which were targeted at China, had little effect on inflation.

“They cost Americans nothing,” he added. “They made a great economy for us.”

Data show that while his earlier tariffs didn’t trigger an inflation surge as was feared, they also didn’t bring a wave of manufacturing and factory jobs to the U.S. as was promised.

During his interview on Meet the Press, Trump also reiterated that tariffs can serve geopolitical functions, claiming that he has prevented wars by threatening steep duties.

“Tariffs are a—properly used—are a very powerful tool, not only economically but also for getting other things outside of economics,” he explained.