US benchmark equity indexes closed mixed on Monday after President Donald Trump warned the administration will impose additional tariffs on China if it does not roll back its retaliatory levies.

The Nasdaq Composite increased 0.1% to 15,603.26, while the S&P 500 fell 0.2% to 5,062.25. The Dow Jones Industrial Average was down 0.9% to 37,965.6. All sectors except communication systems and technology were down. Real estate and materials saw the steepest declines.

US Treasury yields were higher, with the 10-year rate gaining about 14.1 basis points to 4.2% and the two-year rate up 7.8 basis points to 3.7%.

May West Texas Intermediate crude oil decreased 1.7% to $60.96 a barrel on Monday.

Trump said his administration will levy an additional 50% tariff on China, effective Wednesday, unless Beijing reverses its recent retaliatory decisions.

"Additionally, all talks with China concerning their requested meetings with us will be terminated," Trump said in a Monday social media post. "Negotiations with other countries, which have also requested meetings, will begin taking place immediately."

In economic news, the US consumer credit use fell by $800 million in February, compared with a $15 billion increase expected in a survey compiled by Bloomberg.

In company news, Dollar Tree (DLTR) was among the top performers on the S&P 500, with shares gaining 7.8%. Citigroup upgraded the company's rating to buy from neutral and raised the price target to $103 from $76.

Nvidia (NVDA) was the top performer on Dow, with shares up 3.5%.

AppLovin (APP) shares increased 5.9%. Chief Executive Adam Foroughi told MT Newswires that the company's offer for TikTok can "provide a win for the Trump administration and for the creators of TikTok."

SLB (SLB) shares were down 4.8%. TD Cowen and Piper Sandler lowered the price target on the company's stock to $48 from $55 and $46 from $47, respectively.

SUNation Energy (SUNE) shares declined 77%. The company closed the final tranche of its previously announced securities purchase agreement with certain institutional investors, raising $5 million.

Gold dropped 1.5% to $2,989.6 per troy ounce, while silver was up 2.3% to $29.90 per troy ounce.