The United States has imposed new tariffs of up to 12.5 percent on imports from 60 trading partners, including China, the European Union and the UK.
The tariffs, covering nearly all U.S. imports, replace a similar levy that expired today.
Washington said the move targets countries failing to tackle forced labour, while trade experts say the measure is aimed at cutting the U.S. trade deficit and protecting domestic manufacturing.
The US Supreme Court had ruled earlier this year that many of the tariffs imposed globally under emergency powers were illegally enacted.