WASHINGTON (AP) -- President Donald Trump said Friday that "there seems to be no reason" to meet with Chinese leader Xi Jinping as part of an upcoming trip to South Korea after China restricted exports of rare earths needed for American industry.

The Republican president suggested that he was looking at a "massive increase" of import taxes on Chinese products in response to Xi's moves.

"One of the Policies that we are calculating at this moment is a massive increase of Tariffs on Chinese products coming into the United States of America," Trump posted on his Truth Social platform. "There are many other countermeasures that are, likewise, under serious consideration."

The United States and China have been jockeying for advantage in trade talks, after the import taxes announced earlier this year triggered a trade war between the world's two largest economies. Both nations agreed to ratchet down tariffs after negotiations in Switzerland and the United Kingdom, yet tensions remain as China has sought to restrict America's access to the difficult-to-mine rare earth's needed for a wide array of U.S. technologies.

On Thursday, the Chinese government restricted access to the rare earths ahead of the scheduled Trump-Xi meeting. Beijing would require foreign companies to get special approval for shipping the metallic elements aboard. It also announced permitting requirements on exports of technologies used in the mining, smelting and recycling of rare earths, adding that any export requests for products used in military goods would be rejected.

Trump said that China is "becoming very hostile" and that it's holding the world "captive" by restricting access to the metals and magnets used in electronics, computer chips, lasers, jet engines and other technologies.

"I have not spoken to President Xi because there was no reason to do so," Trump posted. "This was a real surprise, not only to me, but to all the Leaders of the Free World."

The U.S. president said the move on rare earths was "especially inappropriate" given the announcement of a ceasefire between Israel and Hamas in Gaza so that the remaining hostages from Hamas' Oct. 7, 2023, attack can be released. He raised the possibility without evidence that China was trying to steal the moment from him for his role in the ceasefire, saying on social media, "I wonder if that timing was coincidental?"