China-based ByteDance owns TikTok, which has its US headquarters in Southern California.
Trump's order contended the step is needed to "deal with the national emergency with respect to the information and communications technology and services supply chain."
The TikTok mobile application has been downloaded some 175 million times in the US and more than a billion times around the world, according to the order.
US President Donald Trump on Thursday signed an executive order barring transactions with the Chinese parent company of social media platform TikTok after 45 days.
"The United States must take aggressive action against the owners of TikTok to protect our national security," the order said.
