WASHINGTON, D.C.: President Donald Trump threatened to impose a new 100 percent tariff on all Chinese imports starting November 1 — or sooner — escalating trade tensions between the world's two largest economies.

The move came after China introduced new export controls on rare earth elements, a group of minerals critical for electronics, jet engines, and other technologies. The Chinese government said foreign companies would now need special approval to export the materials and related technologies, and that any products used in military goods would be banned from export.

Trump criticized the move on social media, calling China's actions "shocking" and "out of the blue." He accused Beijing of "becoming very hostile" and said it was holding the world "captive" by limiting access to key materials.

"Starting November 1, 2025 (or sooner, depending on any further actions or changes taken by China), the United States of America will impose a tariff of 100 percent on China, over and above any Tariff that they are currently paying," Trump said in a post. He also said the U.S. would respond with its own export controls "on any and all critical software" from American firms.

The president later appeared to soften his tone, telling reporters he hadn't canceled a possible meeting with Chinese leader Xi Jinping during his upcoming trip to South Korea. "I'm going to be there regardless, so I would assume we might have it," Trump said. "We're going to have to see what happens. That's why I made it November 1."

The announcement rattled financial markets, sending the S&P 500 down 2.7 percent — its worst day since April, when Trump last floated similarly steep tariffs. Analysts warned that doubling tariffs on Chinese goods, already taxed at 30 percent, could reignite the global trade war and weigh heavily on international growth.

Economists also cautioned that higher tariffs could worsen inflation and strain the U.S. economy just as job growth slows and the effects of a partial government shutdown deepen.

While Trump's message was strong, investors noted his history of backing away from major tariff threats — a pattern some traders jokingly call the "TACO" trade, short for "Trump Always Chickens Out."

The latest Chinese export restrictions have already delayed the global supply of rare earths, the European Union Chamber of Commerce in China said in a statement, warning that the new measures "add further complexity to the global supply chain."

The Chinese Embassy in Washington did not immediately respond to requests for comment from the Associated Press.