HONG KONG — China said Thursday it would take all “necessary measures” to protect its legitimate interests after it was hit particularly hard by President Donald Trump’s sweeping tariffs on U.S. trading partners around the world.

Starting April 9, imports from the world’s second-biggest economy will be subject to an additional U.S. tariff of 34%, Trump said Wednesday at the White House, as he unveiled a long list of what he called reciprocal tariffs. That is on top of 20% in…