Copper futures in New York surged after US President Donald Trump said he planned to implement a 50% tariff on imports, a move that’s likely to spark massive supply-chain ripples through global metal markets.

Prices for the metal hit a record high after the president suggested a higher rate than many analysts were expecting.

Donald Trump's mooted 50% tariff on copper imports into America has sharply exacerbated what was already a dislocation between New York and London prices for the metal. The chart shows that since Trump's inauguration traders have been placing a greater premium on the COMEX contract,