Beginning on Sunday, the hugely popular video app TikTok and the messaging app WeChat will be banned from distribution in the United States, the U.S. Department of Commerce announced Friday morning.

US ban on TikTok and WeChat goes into effect on Sunday

Beginning on Sunday, the video app TikTok and the messaging app WeChat will no longer be available from app stores in the United States, as all new downloads will be blocked under the order of the US Department of Commerce. The order also bans the transfer of funds or processing payments within the U.S. for WeChat. The ban for both apps goes into effect on Sunday.

TikTok is extremely popular among Gen Z (ages 18-23), having an estimated 65 million to 80 million users in the US, while WeChat has an estimated 19 million US users, with a majority of them being people of Chinese descent who mostly use the app to communicate with loved ones or to do business in China.

The Commerce Department said the move was necessary to “safeguard the national security of the United States,” ABC reported.

The Department of Commerce alleges that the Chinese Communist Party was using data collected through both apps to “threaten the national security, foreign policy and the economy of the U.S.”

In August, President Donald Trump issued a pair of executive orders that called for shutting down the apps by September 20 if they were not sold to owners in the United States.

TikTok will continue to work for another three weeks

The app will still work for at least a few more weeks, NBC reported. The Department of Commerce said that certain crucial services that TikTok relies on, such as internet hosting and transit services, will still work for another three weeks, and will not be prohibited until Nov. 12.

According to reports, TikTok is still in negotiations in hopes of making a deal that may stave off a complete ban.

Commerce Secretary Wilbur Ross said in an interview, “Basic TikTok will stay intact until November 12. If there is not a deal by November 12 under the provisions of the old order then TikTok…will be, for all practical purposes, shut down.”

WeChat ban will render app useless as of Monday

Although TikTok will continue to operate for another three weeks, the ban on WeChat will block all services.

Ross said in the same interview that the shut down of WeChat as of midnight on Monday, “for all practical purposes,” will effectively render the app nearly useless.