Despite threats of retaliation from China over U.S. plans to impose tariffs on up to $60 billion in Chinese goods, Treasury Secretary Steve Mnuchin on Sunday said President Donald Trump had no intention of backing down and was not worried about a trade war.

"We are going to proceed with our tariffs. We're working on that," Mnuchin told "Fox News Sunday." "So, as President Trump said, we're not afraid of a trade war, but that's not our objective."

Fears of a trade war between the United States and China have sent U.S. stock prices tumbling. The Dow Jones Industrial Average and the S&P 500 both lost nearly 6 percent by the end of last week.