Apple is expanding its US-made chip roster, but according to TSMC’s CEO, the most modern chips will continue being manufactured elsewhere.

Taiwan Semiconductor Manufacturing Company (TSMC) first announced its plans to build an “advanced semiconductor manufacturing fabrication” facility in Arizona in early 2020, committing to a $12 billion investment in Phoenix that it later increased to a staggering $40 billion when it committed to a second facility in the state.

Apple is already testing the initial batch of processors produced for its devices by TSMC Arizona, reports Nikkei Asia. To begin with, the tests intend to compare the Arizona output to see if the quality is similar to chips produced in TSMC’s cutting-edge fabs in Taiwan.

TSMC's new U.S. plant is unlikely to get the most advanced chip technology before factories in Taiwan due to complex compliance issues, local construction regulations and various permitting requirements,