The order to delete the app was issued by Catherine Szpindor, the chief administrative officer of the House, whose office warned in August that the app represented a “high risk to users” citing a “number of security concerns.”

“House staff are NOT allowed to download the TikTok app on any House mobile devices,” said a memo sent by Szpindor on Tuesday seen by NBC News. “If you have the TikTok app on your House mobile device, you will be contacted to remove it.”

The new ban follows a series of moves by U.S. state governments to remove TikTok, developed by Chinese tech giant ByteDance, from government devices, amid fears that collected data could allow the Chinese government to spy on Americans, or that the app’s algorithm could influence and censor what users watch on the app.

As of last week, 19 states — including Texas, Georgia, Maryland, South Dakota, South Carolina and Nebraska — had at least partially blocked the app from state-managed devices over concerns that the Chinese government could use the app to track Americans and censor content. The U.S. military also banned its service-members from using TikTok on government devices, fearing the app could potentially expose personal data to “unwanted actors.”

A broader measure aimed at banning the app on all federally managed devices was included in the $1.66 trillion federal omnibus spending bill passed last week, which takes effect once President Joe Biden signs the legislation into law.

In response to the spending bill, TikTok said the move was a “political gesture that will do nothing to advance national security interests.” TikTok did not immediately return TechCrunch’s request for comment.

There are also parallel efforts to ban TikTok from consumer devices across the United States.

Earlier this month, Sen. Marco Rubio (R-FL) also proposed legislation that would ban TikTok nationally. When introducing the bipartisan bill, Rubio said that the app allows the Chinese government “a unique ability to monitor more than 1 billion users worldwide, including nearly two-thirds of American teenagers.”

“Unless TikTok and its algorithm can be separated from Beijing, the app’s use in the United States will continue to jeopardize our country’s safety and pave the way for a Chinese-influenced tech landscape here,” he said in a Washington Post article.

TikTok has been a source of security and privacy concerns for several years. ByteDance last week admitted that its employees had accessed the user data of journalists to find the source of leaked company information.