The Dow Jones industrial average fell 0.4% to 42,299.70 points and the broader S&P 500 index lost 0.3% to 5,693.31 points.

The tech-heavy Nasdaq Composite index fell 0.5 percent to 17,804.03.

Analysts said the imposition of the tariffs - with further levy announcements on April 2 - had sent shockwaves through global markets.

"I think there's a lot of confusion right now," said Tom Cahill of Ventura Wealth Management.

Investors had expected more details about Trump's promised duties on April 2, with markets previously lifted by hopes they would be more targeted than expected.

Trump has promised to impose reciprocal tariffs to address practices his administration deems unfair, but the White House has previously signaled that individual actions on individual sectors may not be taken on the same day. 

But Trump's announced 25 percent auto tariffs, which will take effect next week, came unexpectedly for investors, Cahill added.

About half of the cars sold in the U.S. are imported, and the supply chain for North American auto manufacturing includes parts that cross borders multiple times.

That means tariffs are likely to raise costs for consumers.

On March 27, shares of Ford, the largest automaker, fell 3.9% and General Motors fell 7.4%. Stellantis shares fell 1.2%.

While markets have tried to rally, that effort "lacks conviction," Cahill said, as it's risky to get ahead of Trump's April 2 announcement. | BGNES