Donald Trump has signed an executive order that will ban American companies from using telecommunications equipment made by foreign firms posing a national security risk to the US, in a move thought to be aimed at China's Huawei.
The president's move comes as tensions have flared between the two countries, with Beijing and Washington failing to find consensus on trade and tariffs after months of negotiations.
In a statement, White House press secretary Sarah Huckabee Sanders said that the emergency declaration by the president is"part of his commitment to protecting the information and communications technology and services of our Nation."
"The President has made it clear that this Administration will do what it takes to keep America safe and prosperous, and to protect America from foreign adversaries who are actively and increasingly creating and exploiting vulnerabilities in information and communications technology infrastructure and services in the United States," Ms Sanders continued in the statement, which was emailed to reporters.
The West Wing has reportedly been considering the executive order for more than a year, but repeatedly delayed the measure for unknown reasons.
While the press secretary and executive order do not mention any specific country or company by name, the measure comes amid concerns in Washington that Huawei Technologies Co Ltd — the world's largest smartphone manufacturer — could be used by the Chinese government to spy on the US and western allies. The company has repeatedly denied those allegations.
Just before the executive order was signed on Wednesday, Chinese Foreign Ministry spokesman Geng Shuang said during his daily briefing in Beijing that the US had been "abusing its national power" to "deliberately smear" and suppress Chinese companies.
"This is not honourable, nor is it just," he said.
The new executive order represents something of an expansion of US policy already in place since August, when the president signed a bill that barred the US government from using Huawei equipment and goods from another Chinese company, ZTE Corp.
The measure also follows after US prosecutors charged two Huawei units in Washington State with conspiring to steal T-Mobile trade secrets. The chief financial officer for the company was also charged, but for violating sanctions on Iran.
Reuters contributed to this report