According to the Financial Times ARM has been hit by the new US government rules restricting China and Russia exports of powerful chips that could be repurposed for military use.
ARM believes its Neoverse V would fall into the category of high-performance processors affected by the new rules. While it could apply for a license, it would likely be turned down. This is the first time ARM has decided not to sell its most advanced chip designs to China.
ARM's latest Neoverse V2 core has the highest performance to date and its design originated in the US.