President Donald Trump said his 50% tariff on copper imports will take effect on Aug. 1, noting he made the decision after a national security assessment.

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.