The United States has imposed restrictions on exports to China’s biggest chip maker SMIC after concluding there is an “unacceptable risk” equipment supplied to it could be used for military purposes.

Suppliers of certain equipment to Semiconductor Manufacturing International Corporation will now have to apply for individual export licenses, according to a letter from the Commerce Department dated Friday and seen by Reuters.

The latest move marks a shift in US policy from earlier this year, when applicants seeking “military end user” licenses to sell to SMIC were told by the Commerce Department that the licenses weren’t necessary, according to three people familiar with the matter.

SMIC said it had not received any official notice of the restrictions and said it has no ties with the Chinese military.

“SMIC reiterates that it manufactures semiconductors and provides services solely for civilian and commercial end-users and end-uses,” SMIC said. “The Company has no relationship with the Chinese military and does not manufacture for any military end-users or end-uses.”

SMIC is the latest leading Chinese technology company to face US trade restrictions related to national security issues or US foreign policy efforts. Telecoms giant Huawei Technologies had its access to high-end chips curtailed by its addition to a Commerce Department blacklist known as the entity list.

SMIC’s new designation is not as severe as being blacklisted, which makes it difficult to get any export license approved.

The Pentagon earlier this month, Reuters was first to report, said it was working with other agencies to determine whether to blacklist SMIC for its purported links to the Chinese military.

US companies including Lam Research, KLA Corp and Applied Materials, which supply chipmaking equipment, may now need to get licenses to ship certain goods to SMIC. It is unclear which suppliers received the letter, but typically once the Commerce Department comes to the conclusion that there is a risk of military use or diversion, it sends that information to the companies.

The Commerce Department’s Bureau of Industry and Security declined on Saturday to comment specifically on SMIC, but said it was “constantly monitoring and assessing any potential threats to US national security and foreign policy interests”.

The administration has increasingly trained its focus on Chinese companies that bolster Beijing’s military. Last month, the United States blacklisted 24 Chinese companies and targeted people it said were part of construction and military actions in the South China Sea, its first such sanctions against Beijing over the disputed strategic waterway.

Separately, about 3,500 US companies, including Tesla, Ford Motor Co, Target Corp , Walgreen Co and Home Depot have sued the Trump administration in the last two weeks over the imposition of tariffs on more than $300 billion in Chinese-made goods.

The suits, filed in the US Court of International Trade, named US Trade Representative Robert Lighthizer and the Customs and Border Protection agency and challenge what they call the unlawful escalation of the US trade war with China through the imposition of a third and fourth round of tariffs.

The legal challenges from a wide variety of companies argue the Trump administration failed to impose tariffs within a required 12-month period and did not comply with administrative procedures.

The companies challenge the administration’s “unbounded and unlimited trade war impacting billions of dollars in goods imported from the People’s Republic of China by importers in the United States,” according to a suit filed by auto parts manufacturer Dana Corp.

The suits challenge tariffs in two separate groups known as List 3 and List 4A.” List 3 includes 25% tariffs on about $200 billion in imports, while List 4A included 7.5% tariffs on $120 billion in goods.

One suit argues the administration cannot expand tariffs to other Chinese imports “for reasons untethered to the unfair intellectual property policies and practices it originally investigated.”

companies filing suit include heavy truck manufacturer Volvo Group North America, US auto parts retailer Pep Boys, clothing company Ralph Lauren, Sysco Corp, guitar manufacturer Gibson Brands, Lenovo’s US unit, Dole Packaged Foods, a unit of Itochu Corp and golf equipment manufacturer Callaway Golf Co.

Home Depot’s suit noted it faces tariffs on bamboo flooring, cordless drills and many other Chinese-made products. Walgreen, a unit of the Walgreen Boots Alliance, said it is paying higher tariffs on products like “seasonal novelties; party, first aid, and office supplies; and household essentials.”

Lighthizer’s office did not immediately respond to requests for comment.

Reuters