US benchmark equity indexes closed lower on Wednesday as markets await President Donald Trump's announcement of tariffs on US auto imports.

The Nasdaq Composite fell 2% to 17,899, while the S&P 500 decreased 1.1% to 5,712.2. The Dow Jones Industrial Average was down 0.3% to 42,454.8. Consumer staples and utilities sectors had the biggest gains, and technology saw the steepest decline.

US Treasury yields were higher, with the 10-year rate gaining about 2.7 basis points to 4.3% and the two-year rate was up 4.1 basis points to 4%.

May West Texas Intermediate crude oil increased 1.1% to $69.78 a barrel on Wednesday.

The Trump administration may impose tariffs on copper imports in the coming weeks, well ahead of a deadline for a decision, Bloomberg reported Wednesday, citing unnamed sources.

In economic news, US durable goods orders saw an unexpected gain last month, with significant growth in defense aircraft and motor vehicle orders, according to government data.

"The underlying trend (in durable goods orders) has turned up recently, improving prospects for the struggling factory sector," BMO Capital Markets said.

Mortgage applications in the US dropped for a second consecutive week as refinancing activity reached its lowest level in a month, the Mortgage Bankers Association said.

In company news, Cintas (CTAS) was the top gainer on the S&P 500, with shares up 5.8%. The uniform supplier raised its full-year earnings outlook after its fiscal third-quarter results topped Wall Street's views.

Paychex (PAYX) was up 4.2%. The company reported higher-than-expected fiscal Q3 earnings driven by revenue growth across its two main segments.

Nvidia (NVDA) shares fell 5.7%. The company is moving closer to a deal to buy Lepton AI, a startup that rents out servers powered by Nvidia's AI chips, The Information reported.

Tesla shares were down 5.6%. The company's customers in Canada will no longer be eligible for electric vehicle rebates following an order by Transport Minister Chrystia Freeland, news outlets reported.

Gold dropped 0.1% to $3,022.50 per troy ounce, while silver was down 0.2% to $34.11 per troy ounce.