U.S. economic growth will slow to 1.6% this year from 2.8% last year as Donald Trump’s erratic trade wars disrupt global commerce, drive up costs and leave businesses and consumers paralyzed by uncertainty.

The Organization for Economic Cooperation and Development forecast Tuesday that the U.S. economy — the world’s largest — will slow further to just 1.5% in 2026. Trump’s policies have raised average U.S. tariff rates from around 2.5% when he returned to the White House to 15.4%, highest since 1938, according to the OECD. Tariffs raise costs for consumers and American manufacturers that rely on imported raw materials and components.

World economic growth will slow to just 2.9% this year and stay there in 2026, according to the OECD’s forecast. It marks a substantial deceleration from growth of 3.3% global growth last year and 3.4% in 2023.