US authorities announced a ban Friday on the import or sale of communications equipment deemed "an unacceptable risk to national security" -- including gear from Chinese giants Huawei Technologies and ZTE.
Both firms have been on a roster of companies listed as a threat by the Federal Communications Commission (FCC), and the new rules bar future authorizations of their equipment.
The move is the latest in a series of actions to limit the access of Chinese telecoms firms in United States networks, and comes amid a long-running standoff between the world's two biggest economies.
US officials have shown growing wariness in recent years of Chinese telecommunications companies and technology.
"The FCC is committed to protecting our national security by ensuring that untrustworthy communications equipment is not authorized for use within our borders," said the commission's chairwoman Jessica Rosenworcel in a statement.
She added that the new rules are a part of ongoing work to guard against security threats.
The order also affects companies including video surveillance equipment firms Hangzhou Hikvision and Dahua Technology.
The FCC said Friday that it was also seeking comment on future action relating to existing authorizations.
Previously, Washington had banned Huawei from supplying US government systems and strongly discouraged the use of its equipment in the private sector, with fears that Huawei equipment could be compromised by Chinese intelligence.
In 2019, it put Huawei on a trade blacklist that barred US suppliers from doing business with it, cutting the Chinese firm -- also a top smartphone brand -- off from Google's Android mobile operating system.
The US has cited national security fears as well to restrict the operations of China's big three state-owned mobile carriers.