WASHINGTON (Reuters) - U.S. Treasury Secretary Janet Yellen said on Tuesday she was worried that President-elect Donald Trump's plans to levy broad import tariffs could derail progress in quelling inflation and raise costs for households and businesses.

Yellen, at a Wall Street Journal CEO Council event, also said she was concerned about U.S. fiscal sustainability and said Congress needed to look for ways to pay for any extensions of Trump's 2017 individual and small-business tax cuts, which are due to expire in 2025.