U.S. President Donald Trump's threat of a 50% tariff on copper imports is raising alarm in the U.S. auto sector, as it could make it even harder for carmakers and suppliers to absorb border taxes and rising costs,

Comex copper for July delivery jumped 66.05 cents per pound, or 13%, to close at $5.645. That's a record high and the biggest single-day gain ever for copper, according to Dow Jones Market Data. The metal is up 41.6% year to date and up 23.3% over the past 52 weeks. In after-hours trading, the metal traded at $5.48 per pound, according to FactSet.

WASHINGTON (Reuters) -President Donald Trump said on Tuesday he will announce a 50% tariff on copper later in the day, aiming to boost U.S. production of a metal critical to electric vehicles, military hardware, the power grid and many consumer goods.