President Donald Trump, on Wednesday, extended the existing ban on U.S. companies using telecommunications equipment made by firms that pose a national security risk — including Chinese manufacturer Huawei.

The U.S. government’s decision is largely aimed at Huawei, though ZTE, another Chinese phone hardware manufacturer, is included in the ban.

The order originated in 2019, at the height of the U.S.-China trade war. Dubbed the International Economic Powers Act, it gave the president the right to regulate commerce during a national emergency that threatened the U.S.

The move prevents companies like Huawei from buying U.S. technology and components without a waiver from the U.S. government. Many of those companies rely heavily on American chip manufacturers and other technology firms for their electronic products, though Huawei makes and uses it own chipsets and modems, and also works with British chip maker ARM.

The ban also means Huawei cannot pre-install apps from popular social media sites, including Facebook, Twitter, Instagram, and WhatsApp.

Before the Huawei ban went into effect, the company had a fairly broad U.S. presence. A report in the New York Times estimates that the company sold equipment for roughly 25% of all small U.S. wireless firms. The executive action did away with a low-priced alternative for people in rural areas.

Huawei, while it can’t sell in the U.S., has strong operations in the rest of the world. It recently introduced a new operating system, since it cannot use any recent updates to Google’s Android OS.