U.S. customs authorities will face a real challenge if President Donald Trump goes through with his threat to place tariffs on six EU countries - rather than the whole European Union - given the ease of movement of goods between EU members.

Gold and silver hit record highs on Monday while equity markets fell after Donald Trump revived trade war fears by threatening several European nations with tariffs over their opposition to the United States buying Greenland.

European Commission President Ursula von der Leyen said President Trump’s additional tariffs on nations that oppose his demand to take control of Greenland were a mistake. “Arctic security can only be achieved together,

Calls are growing louder for the European Union to deploy its powerful "anti-coercion instrument" in response to US President Donald Trump's threats to impose tariffs in the standoff over Greenland.