TikTok will be banned on UK government phones after security concerns were raised about use of the Chinese-owned app.
Cabinet Office minister Oliver Dowden told the House of Commons that government devices would only be able to access third party apps from a pre-approved list.
"We are also going to ban the use of TikTok on government devices. We will do so with immediate effect," he said.
The ban does not include personal devices and there will be limited exemptions where TikTok is required on government devices for operational reasons, Mr Dowden added.
"This is a proportionate move based on a specific risk with government devices."
Prime Minister Rishi Sunak has been under pressure from senior MPs to follow the United States and European Union in banning the social media app from government devices.
The ban is being imposed over risks around how sensitive information can be accessed by TikTok.
TikTok said bans have been based on "misplaced fears and seemingly driven by wider geopolitics", saying it would be "disappointed by such a move" in the UK.
Downing Street account may be 'exempt'
Downing Street has appeared to suggest it could exercise a "specific exemption" to keep its TikTok account open for communication reasons following the decision to ban the video-sharing app on government devices.
A spokesperson for Mr Sunak said: "We've set out that there will be a process for specific exemptions and comms is one area where there is a potential exemption.
"We obviously want to continue to use social media platforms to engage with audiences and that won't change."
Downing Street said earlier that there was no plan to delete the No 10 account.
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