Global stock markets fell on Monday after President Donald Trump announced that the United States will double tariffs on imported steel and aluminum to 50% starting Wednesday, escalating trade tensions with China. The move followed accusations by Trump that China violated a recent trade truce agreed in Geneva, which Beijing denied, calling the charges groundless. The Geneva truce had paused new tariffs for 90 days. Asian markets led the declines, with indices in Hong Kong, Tokyo, Sydney, Singapore, Taipei, Manila, and Jakarta closing lower, while Shanghai was closed for a public holiday. European and U.S. markets also retreated, with the Dow Jones Industrial Average down 0.49% to 42,061.61, the S&P 500 falling 0.27% to 5,895.91, and the Nasdaq slipping 0.05% to 19,103.67. Shares of U.S. steel companies such as Cleveland-Cliffs, Nucor, and Steel Dynamics rose sharply, while automakers like Ford and General Motors fell more than 4%. The S&P 500 had logged its best monthly performance in 18 months in May. The U.S. dollar weakened broadly, with the dollar index at 98.63, reaching a near three-year low against a basket of major currencies. The euro rose 0.8% to $1.1437 and the yen gained 0.9%. The drop in the dollar was attributed to concerns over the impact of higher tariffs on U.S. growth and inflation, as well as fiscal worries related to a proposed $3.8 trillion increase in U.S. government debt. The US ISM manufacturing PMI for May was 48.5, below the forecast of 49.3. China responded to the tariff announcement by promising to take forceful measures to safeguard its interests and criticized new U.S. restrictions on technology exports and visa revocations. The European Union warned of possible countermeasures if its exports are affected. U.S. Treasury Secretary Scott Bessent said President Trump and Chinese President Xi Jinping are expected to resume talks to address the trade dispute. Oil prices rose nearly 4% after OPEC+ maintained its planned output increases for July, with Brent at $64.85 per barrel and WTI at $62.88 per barrel. Gold prices climbed 2% to $3,356 per ounce. Moody's downgraded the U.S. credit rating, and JPMorgan CEO Jamie Dimon warned of potential challenges in the bond market. In Brazil, the Ibovespa was up 0.01% at 137,035.91 points, and the dollar index fell 0.57%.