(Reuters) -The United States is making it more difficult for chipmakers Samsung and SK Hynix ( HXSCF ) to produce chips in China by revoking authorizations that allowed the companies to receive American semiconductor manufacturing equipment there, according to the Federal Register.

The U.S. Commerce Department had given the companies exemptions to sweeping restrictions created in 2022 on the sale of U.S. semiconductor equipment to China.

The companies will now need to obtain licenses to buy the equipment for China. The federal filing also included Intel ( INTC ) among the companies that lost their authorization for China, although Intel ( INTC ) sold its Dalian China unit in a deal that was finalized this year.

The revocations will take effect in 120 days, according to the posting.

The Commerce Department said in a statement that the United States plans to grant license applications to allow the companies to operate their existing facilities in China, but does not intend to grant licenses to expand capacity or upgrade technology.

SK Hynix ( HXSCF ) said in a statement that it "will maintain close communication with both Korean and the U.S. governments and take necessary measures to minimize the impact on our business."

Samsung did not respond to a request for comment.

South Korea's government has explained to the Commerce Department "the importance of a stable operation of our semiconductor companies in China for the stability of the global semiconductor supply chain," the industry ministry said.

Seoul will continue discussions with Washington to minimize the impact on South Korean companies, the ministry said.

The licensing change will likely reduce sales to China by U.S. equipment makers KLA Corp ( KLAC ), Lam Research ( LRCX ) and Applied Materials ( AMAT ). The companies did not immediately respond to requests for comment.

Shares of Lam fell 4.4%, Applied Materials ( AMAT ) dropped 2.9% and KLA shares were down 2.8%.

CHINESE MAKERS, MICRON MAY BENEFIT

In June, when the Commerce Department raised the possibility of revoking the authorizations, a White House official said the United States was "just laying the groundwork" in case the truce in trade talks between the two countries fell apart.

In July, the two allies and major trading partners announced a deal on tariffs, but South Korean President Lee Jae Myung came away from a summit with U.S. President Donald Trump this week without finalizing the agreement in writing.

The United States and China are operating under a tariff truce, with levies of 30% on Chinese imports to the U.S. and 10% Chinese duties on U.S. goods locked in until November. The trade war between the world's two largest economies has affected everything from rare earths needed by U.S. industry to China's purchase of U.S. soybeans.

The White House did not have an immediate comment.

"This move will make it harder for Korean chipmakers with facilities in China to continue producing more advanced chips," said Chris Miller, author of "Chip War."

The move may help domestic Chinese equipment makers, whose tools can fill gaps. It also may help Micron, a major U.S. competitor to South Korea's Samsung and SK Hynix ( HXSCF ) in the memory chip sector.

"If this isn't accompanied by further steps against (Chinese chipmakers like) YMTC and CXMT, it risks opening market space for Chinese firms at the expense of the Korean firms," Miller said.

Thousands of license applications by U.S. companies to export goods and technology to China also have been in limbo in recent months, creating a massive backlog, as Reuters reported this month, including for billions of dollars' worth of semiconductor manufacturing equipment.

Foreign chipmakers like Samsung and Hynix ( HXSCF ) now have what is known as Validated End User status, which allows U.S. suppliers to ship goods to them "more easily, quickly and reliably," as the Commerce Department says on its website, than they would if export licenses were required. That VEU status will be removed.