President Donald Trump on Friday threatened China with a "massive" increase in tariffs in retaliation for Beijing imposing strict controls on rare earths.

Stock markets dropped on Trump's bellicose Truth Social post that said China is "becoming very hostile" in seeking tough export controls on rare earths.

Stocks tied to rare earths jumped after Trump threatened countermeasures against China, noting the country was holding the world "captive" over the metals.

After Beijing announced new controls on foreign-made products containing Chinese rare earths, Donald Trump threatened to impose an additional 100% tariff as soon as November 1.

President Donald Trump on Friday threatened China with a "massive" increase in tariffs in retaliation for Beijing imposing strict controls on rare earths.

The last week could just be a preview to China weaponizing its entire supply chain, the investor told Fortune.

Shares of U.S. rare earth miners rallied in premarket trade on Tuesday, extending sharp gains from the previous session.

China will not allow the export of rare earth materials for use by foreign militaries under restrictions announced last week.

As the trade war continues to escalate, China has hit back at Trump by suspending exports of rare earth minerals.