Commerce Department assistant secretary for export administration Thea Kendler told a House Foreign Affairs Committee oversight panel that neither the performance nor yields may match the device's market.

"The semiconductor chip inside that phone is a poorer performance than what they had years ago. So our export controls are meaningful in slowing China's advanced technology acquisition," she said.

Republicans are pressuring the US Commerce Department's Bureau of Industry and Security to be tougher on Huawei and its chipmaking partner, Semiconductor Manufacturing International Corp.

Foreign Affairs Committee Chairman Michael McCaul and others have called for the Bureau of Industry and Security to cut off both firms from their American suppliers fully.

US Commerce Secretary Gina Raimondo told Bloomberg News that the US will take the "strongest possible" action to protect its national security while declining to confirm the existence of an investigation into Huawei or SMIC.