United States President Donald Trump's proposed 50% tariff on copper imports would affect Mexican exports worth around US $1 billion per year.

"This is a terrible idea and will have a significant impact on the tech sector," warns Matt Mittelsteadt, a technology policy expert with the Cato Institute. Raising copper prices via tariffs will "massively strain the infrastructure that powers innovation," he added.

U.S. President Donald Trump's 50% tariff on copper has placed a record premium on prices of the metal in the United States that is likely to ease over the coming months as a stockpile created by traders anticipating the levy works through the system.

The president has published just 22 letters, many to minor trading partners like Brunei, Moldova and Sri Lanka.

“The U.S. has been sucking in lots of copper that it didn’t really need from around the world,” Albert Mackenzie is a copper analyst at Benchmark Mineral Intelligence. President Trump had signaled that the tariffs were coming months ago, prompting many U.S. buyers to stockpile copper ahead of time.

Goldman Sachs said on Wednesday that copper shipments into the United States are expected to accelerate in the coming weeks following U.S. President Donald Trump's announcement of a 50% tariff on imported copper.

Chile, the world's biggest copper producer, said Wednesday it was awaiting an "official" follow-up on US President Donald Trump's announcement of a 50 percent tariff on imports of the metal. State-owned copper giant Codelco,