BEIJING — President Donald Trump says the U.S. lost a trade war with China “years ago.”

In a tweet Wednesday after China announced a list of U.S. products that might be subject to a 25 percent tariff, Trump said: “We are not in a trade war with China, that war was lost many years ago by the foolish, or incompetent, people who represented the U.S.”

China announced tariffs worth $50 billion on a series of U.S. products including soybeans, whiskey and cars.

Chinese officials said they were obliged to act after the U.S. announced plans for retaliatory tariffs in an escalating dispute over China’s technology program and other trade issues.

William Zarit, chairman of the American Chamber of Commerce in China, says Beijing’s potential retaliation in an escalating dispute with Washington is a concern for every U.S. company doing business in China.

Zarit told The Associated Press in an interview Wednesday that proposed tit-for-tat tariff hikes by both sides would first hit global stock markets.

Zarit said he still hopes Washington and Beijing will not follow through on their threats.

Instead they should work toward a “serious negotiation.”

U.S. business groups mostly agree that something needs to be done about China’s aggressive push in technology. But they worry that China’s measures targeting U.S. exports of aircraft, soybeans and other products could help bring on a tit-for-tat trade war of escalating sanctions between the world’s two biggest economies.