Key U.S. lawmakers are pressing the Biden administration to block Huawei Technologies suppliers from buying American chipmaking gear, escalating efforts to prevent the sanctioned Chinese telecom giant from making progress on semiconductor manufacturing.

The top Republican and Democrat on the House China Select Committee outlined their concerns in a letter Wednesday to Commerce Secretary Gina Raimondo, whose agency oversees a pivotal trade restriction list, as well as broader export controls on advanced chips and manufacturing tools.

They pointed to Chinese companies Pengxinxu, SwaySure Technology, Qingdao Si’En and "potentially many others” as likely members of Huawei’s "clandestine network,” citing Bloomberg reporting.