(Reuters) – Wall Street’s main indexes dipped on Monday after President Donald Trump said he plans to double tariffs on imported steel and aluminum, fueling more uncertainty around U.S. trade policies.

Trump said late on Friday he planned to increase tariffs on imported steel and aluminum to 50% from 25% starting Wednesday, just hours after he accused China of violating an agreement.

Shares of U.S. steel companies rose, with Cleveland-Cliffs jumping 28.3%, Nucor up 11.5% and Steel Dynamics 11.3% higher.

However, shares of automakers fell. Ford and General Motors both were down more than 4%.

“People have been thinking about that (steel tariffs) and trying to formulate the economic impact. It presents the markets with a lot of uncertainty right now,” said Peter Andersen, founder at Andersen Capital Management.

The increased levies risk deepening Trump’s global trade war, and dousing enthusiasm in markets stemming from the U.S. president’s softer trade stance that drove a recovery in risky assets last month.

A temporary relief on some levies on China and a rollback of steep tariff threats on the European Union, along with strong earnings and improving economic picture helped the benchmark S&P 500 log its best monthly performance in 18 months in May.

Also fueling risk-off moves in global markets, Kyiv struck some of Moscow’s nuclear-capable bombers on Sunday, renewing concerns around further escalation of the war.

At 10:31 a.m. ET, the Dow Jones Industrial Average fell 208.46 points, or 0.49%, to 42,061.61, the S&P 500 lost 15.78 points, or 0.27%, to 5,895.91 and the Nasdaq Composite lost 10.10 points, or 0.05%, to 19,103.67.

Eight of the 11 major S&P 500 sub-sectors fell, with consumer discretionary stocks declining the most with an about 1% fall. On the flip side, energy rose 0.8% tracking a rise in oil prices.

U.S.-listed energy stocks advanced after producer group OPEC+ kept output increases in July at the same level as the previous two months.

Most megacap and growth stocks were down, with Tesla leading losses with a 2.5% decline after it reported lower monthly sales for Portugal, Denmark and Sweden.

On the economic front, the Institute for Supply Management’s (ISM) gauge of manufacturing activity came in at 48.5 for May, below estimates of 49.3, according to economists polled by Reuters.

Focus will be on comments from Federal Reserve Chair Jerome Powell later in the day as he presents opening remarks before the Federal Reserve Board International Finance Division’s 75th anniversary conference at 1:00 p.m. ET (1700 GMT).

Investors are also looking ahead to a crucial nonfarm-payrolls report on Friday to gauge the U.S. labor market’s strength amid tariff volatility.

Declining issues outnumbered advancers by a 1.84-to-1 ratio on the NYSE and by a 1.43-to-1 ratio on the Nasdaq.

The S&P 500 posted 10 new 52-week highs and four new lows, while the Nasdaq Composite recorded 51 new highs and 63 new lows.

—

(Reporting by Kanchana Chakravarty and Sukriti Gupta in Bengaluru; Editing by Maju Samuel)