TikTok has been banned on all federal government devices in the US, with limited exceptions, after Joe Biden signed a $1.7tn (£1.4tn) spending bill on Thursday containing a provision that outlaws the China-based app over growing security concerns.

The ban – which was approved by Congress in a vote last week – is a major step targeting the fastest-growing social media platform in the world as opponents express worry user data stored in China could be accessed by the government.

Various government agencies will develop rules for implementing the ban over the next two months. It will mean that federal government employees are required to remove TikTok from their government-issued devices unless they are using the app for national security or law enforcement activities.

It follows a flurry of legislative action against the platform in the US, after more than a dozen governors have issued similar orders prohibiting state employees from using TikTok on state-owned devices. Earlier this week, Congress passed legislation to ban TikTok on devices issued to members of the House of Representatives.

TikTok did not immediately respond to request for comment. In a statement released after the initial House ban, TikTok said the move was a “political gesture that will do nothing to advance national security interests”.

Meanwhile, there has been a push to ban TikTok outright in the US, with legislation introduced by Senator Marco Rubio earlier this month to “ban Beijing-controlled TikTok for good”. That bill echoes moves from the previous administration, after Donald Trump issued an executive order in August 2020 prohibiting US companies from doing business with TikTok’s parent company ByteDance.

The order was later revoked by Biden in June 2021 under the condition that the US committee on foreign investment conducted a security review of the platform and suggested a path forward. That investigation has been ongoing for several years.

Although ByteDance is based in China, the company has long claimed all US user data is stored in data centers in Virginia and backed up in Singapore.

But political pressure began to build anew after BuzzFeed reported in June that China-based ByteDance employees had accessed US TikTok user data multiple times between September 2021 and January 2022.

Legislators have expressed concern that the Chinese Communist party could manipulate young users with pro-China content on its algorithmic home page and access sensitive user data.

“TikTok, their parent company ByteDance, and other China-based tech companies are required by Chinese law to share their information with the Communist party,” Senator Mark Warner said in July when calling for further investigation of the platform.

“Allowing access to American data, down to biometrics such as face prints and voice prints, poses a great risk to not only individual privacy but to national security,” he added.

The legislative pressure on TikTok comes as the app has exploded in popularity in recent years, amassing a user base of more than 1 billion after reporting a 45% increase in monthly active users between July 2020 and July 2022. In 2022 it became the most downloaded app in the world, quietly surpassing longstanding forebears Instagram and Twitter.

With the meteoric rise has come broad concerns about the app’s impact on its relatively young users. Nearly half of people between 18 and 30 in the US use the platform, a recent Pew Research Center report showed – and 67% of users between the ages of 13 and 18 use the app daily.