U.S. President Donald Trump on Tuesday said he would impose a 50% tariff on imported copper and soon introduce long-threatened levies on semiconductors and pharmaceuticals, broadening his trade war that has rattled markets worldwide.

U.S. trading partners are weighing responses after President Donald Trump’s latest action on tariffs sparked a stock market selloff Monday. The White House sent letters yesterday to about a dozen countries laying out the rates at which imports would be taxed—ranging from 25% to 40%—if no other trade agreements are reached.

The U.S.’s closest security allies in Asia, along with six Southeast Asian countries, have been given another three weeks to negotiate trade deals — or face higher tariffs.