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.

The twists and turns in U.S. President Donald Trump's tariff policies have not only rattled global financial markets but have also taken investors on a roller-coaster ride. Companies are counting the cost of the trade war that is now being estimated at more than $34 billion in lost sales and higher expenses,