Short video app TikTok said on Thursday it is ready for large-scale business exploration in North America after the company agreed to settle with the United States Federal Trade Commission for $5.7 million as its sister app was accused of violating local rules.

The US government agency launched an investigation on Musical.ly, a popular lip-sync video app in 2016, suspecting it has violated the Children's Online Privacy Protection Act, which requires that developers or websites targeted at children under 13 must require parental consent to share personal information.

The app was later acquired by Chinese multimedia giant Bytedance in 2017 and merged with TikTok the next year.

"While we were 'accidentally' embroiled in this case, we've been actively in touch with the FTC," said a TikTok representative for North America in a written reply to China Daily. "With the current settlement, we are given green light to expand our business scope."

Due to the investigations, TikTok did not introduce personalized ads services in the US.

According to data from app intelligence firm Sensor Tower, TikTok's monthly downloads have been frequently higher than those of Facebook, Instagram, Snapchat and YouTube in the US since late last year.

Meanwhile, total download of Douyin (the Chinese mainland version) and TikTok on App Store and Google Play have topped 1 billion, including 663 million downloads recorded in 2018. That of Facebook reached 711 million and Instagram were 444 million last year.