WASHINGTON, March 21 (Reuters) - China's top sanctioned

chipmaker SMIC may have violated U.S. export regulations by

producing a chip to power Huawei's Mate 60 Pro phone, a senior

Commerce Department official said during a hearing on Thursday.

When asked by Congressman Michael McCaul if SMIC broke U.S.

export rules to produce the chip, Alan Estevez, who oversees

export policy, said "potentially yes, we will have to assess."