Arm Holdings has instructed employees to stop “all active contracts, support entitlements, and any pending engagements” with Chinese smartphone and telecom equipment manufacturer Huawei, according to a BBC report on Wednesday. Although Arm Holdings was founded in and remains headquartered in the UK, the company was purchased in 2016 by Japanese firm SoftBank.

While this non-US ownership and operation would plausibly make the firm exempt from President Trump’s executive order restricting US firms from doing business with Huawei, Arm does maintain offices in the US. The instruction-set architecture (ISA) technology it licenses to companies including Apple, Qualcomm, Samsung, and HiSilicon–Huawei’s system-on-a-chip (SoC) design subsidiary–contains “US origin technology” as well, according to the memo cited in the BBC report.

Of note, SoftBank’s own-brand mobile network operation in Japan, as well as their Y! Mobile subsidiary have terminated sales of Huawei P30 series phones, which were scheduled to start on Friday. Likewise, Taiwan’s state-owned Chunghwa Telecom has halted “buying new Huawei devices for sale as of now,” according to Nikkei Asian Review, which also quotes Taiwan Mobile as stating that “we will not sell new Huawei smartphones, given that those would not be supported by Google’s services,” undercutting Huawei’s potential hopes of replacing Android with their “plan B” OS, in development since 2012.

SEE: 10 signs you might be working for the wrong company (free PDF) (TechRepublic)

Arm’s severing of ties cuts deeper than similar actions from Intel, Qualcomm, Broadcom, Qorvo, Xilinx, Infineon, Micron, and Western Digital, as Arm-licensed designs are used across a number of business units at Huawei, including their server equipment and telecommunications divisions, which utilize Arm-powered processors produced by HiSilicon.

The immediacy of impact on Huawei’s day-to-day operations is unclear, for a variety of reasons. Arm’s cessation of cooperation involves new licenses–as Huawei already licensed ARMv8, and has the requisite information and expertise to manufacture chips based on the technology, they can continue to produce ARMv8-powered SoCs without the involvement of Arm Holdings. Further, the relatively long lead time for chip design and manufacturing gives Huawei ample breathing room before impact is felt across other business units. Huawei has also reportedly stockpiled at least three months of chips from other vendors, in anticipation of being caught in the middle of a trade dispute between the US and China.

Huawei previously showcased the Arm-based Kunpeng 920 CPU at CES 2019, and three TaiShan server models utilizing the CPU, putting the company in competition with Cavium and Qualcomm, producers of the ThunderX2 and Centriq Arm server processors, respectively, and with Amazon’s Graviton CPU, which is only available as part of the EC2 offering on Amazon Web Services (AWS). The relatively nascent Arm-powered server market had gained momentum following the Spectre and Meltdown vulnerabilities that exploited hardware design flaws in the x86-64 ISA, which disproportionately affected Intel.

For more on Huawei, check out “Google’s problems in China are bigger than Huawei” at CNET, and “Huawei ban could hurt chipmakers, raising fears of tech layoffs” at CBS News.