ASML, the most advanced maker of equipment for producing semiconductors, told its employees in the U.S. to refrain from servicing customers in China following new regulations from the Biden administration, according to an internal email sent to staff.

“ASML U.S. employees must refrain — either directly, or indirectly — from servicing, shipping or providing support to any customers in China until further notice, while ASML is actively assessing which particular fabs are affected by this regulation,” according to an email from the U.S. management team addressed to employees in the country. The ban applies to all U.S. employees, including American citizens, green card holders and foreign nationals who live in the country, according to the email. 

The U.S. has banned Chinese companies from buying advanced chip-making equipment or employing American citizens without a license, to prevent the Communist Party from becoming more of an economic and military threat. 

The Veldhoven, Netherlands-based ASML has had to strike a challenging balance between the U.S. and China. It has been selling its deep ultraviolet, or DUV, machines to Chinese customers but has held back from offering its more advanced extreme ultraviolet, or EUV, machines. 

ASML head of corporate communications Monique Mols confirmed that the email that circulated on social media on Wednesday “is indeed a genuine communication but it was not intended to be shared externally.” 

“We are of course taking precautionary measures in order to ensure full compliance with the new regulations while we are assessing the new Export Control restrictions,” Mols said in an email. “As the memo says, further instructions to our employees will follow once we have done the assessment.”

ASML’s move comes as American suppliers are beginning to withdraw staff from one of China’s leading chip companies in the wake of the same regulations. Applied Materials, KLA and Lam Research have started or are preparing to pull employees from Yangtze Memory Technologies, the country’s most advanced maker of memory chips, Bloomberg reported Wednesday.