Global economic growth is set to be slower this year largely because of Donald Trump's US tariffs, according to a leading international policy group. Worldwide growth is now expected to slow to 2.9%, down from a previous forecast of 3.1%, said the Organization for Economic Co-operation and Development (OECD).

Donald Trump’s combative trade policies have tipped the world economy into a downturn clouded in heightened uncertainty, with the US among the hardest hit, the OECD said.

Wall Street's main indexes opened lower on Monday after President Donald Trump revealed plans to double tariffs on imported steel and aluminum, fueling more uncertainty around U.S. trade policies. The Dow Jones Industrial Average fell 70.

US states and small businesses that won a ruling that most of President Donald Trump’s global tariffs are illegal want them blocked during the administration’s appeal, saying they’re suffering immediate harm from economic uncertainty around the levies.

On tariffs, the courts have directed Donald Trump to work with a Republican-led Congress on a new law. By the president's own admission, he doesn’t want to.

The president's plan - where countries face between 11% to more than 100% tariffs on goods brought into the US - was announced in April. But the majority of the tariffs were paused by Trump for 90 days in the wake of stock market volatility.

The looming legal fight injects uncertainty into President Donald Trump's evolving tariffs plan, which has upended the global economy since April 2.

President Trump warns of potential 'economic ruin' if courts do not uphold his massive, unilateral tariffs. In a rare admission, he suggests these tariffs could be counterproductive, especially if foreign retaliatory measures persist.