The fact was revealed in an internal letter sent by the lab's chief information officer to the National Nuclear Security Administration's assistant manager for safeguards and security.
It seems to imply that even though there is no evidence that the devices in question are compromised in any way, the recent recommendation by the U.S. House of Representatives' Permanent Committee on Intelligence for U.S. companies and agencies to avoid using devices manufactured by ZTE and Huawei has produced the hoped-for effect.
It seems that no matter the assurances and offers of testing equipment and source code by the hands of government and independent security experts, U.S. government agencies might have already decided to err on the side of caution and are looking to minimize the attack surface as much as possible.
The Australian government also took its cue from those views and has recently decided not to let Huawei compete for lucrative national contracts. The reaction of these two countries is generally thought to have triggered state-owned telecom China Unicom's decision to replace all Cisco System devices from one of its major backbone networks.
The letter sent by Los Alamos' CIO appears to be a reply to the House Armed Services Committee for the Department of Energy's request for a report on possible supply chain risks.
The Los Alamos laboratory and the National Nuclear Security Administration are yet to comment on the letter.