NEW YORK • The United States government has launched a national security review of TikTok owner Beijing ByteDance Technology Co's US$1 billion (S$1.36 billion) acquisition of US social media app Musical.ly, according to three people familiar with the matter.

While the acquisition was completed two years ago, US lawmakers in recent weeks have been calling for a national security probe into TikTok, concerned that the Chinese company may be censoring politically sensitive content, and raising questions about how it stores personal data.

TikTok has been growing popular among American teenagers at a time of increasing tensions between Washington and Beijing over trade and technology transfers.

About 60 per cent of TikTok's 26.5 million monthly active users in the US are between the ages of 16 and 24, the company said this year.

The Committee on Foreign Investment in the United States (CFIUS), which reviews deals by foreign acquirers for potential national security risks, has started to review the Musical.ly deal, the sources said.

TikTok did not seek clearance from CFIUS when it acquired Musical.ly, they added, which gives the US security panel scope to investigate it now.

"While we cannot comment on ongoing regulatory processes, TikTok has made clear that we have no higher priority than earning the trust of users and regulators in the US.

"Part of that effort includes working with Congress and we are committed to doing so," a TikTok spokesman said.

REUTERS, BLOOMBERG