FILE PHOTO: Tik Tok logo is displayed on the smartphone while standing on the U.S. flag in this illustration picture taken, November 8, 2019. REUTERS/Dado Ruvic

WASHINGTON (Reuters) - The top Democrat in the U.S. Senate, Chuck Schumer, on Tuesday released a letter he wrote to Army Secretary Ryan McCarthy raising concerns about the U.S. military’s use of the China-owned TikTok social media platform for recruiting American teenagers.

“While I recognize that the Army must adapt its recruiting techniques in order to attract young Americans to serve, I urge you to assess the potential national security risks posed by China-owned technology companies before choosing to utilize certain platforms,” Schumer wrote in the letter dated Nov. 7.

TikTok, a video app popular with teens and 20-somethings, has grown more popular among U.S. teenagers at a time of mounting tensions between Washington and Beijing over trade and technology transfers. The company has stressed its independence from China but has failed to calm congressional nerves about security of the personal data of U.S. citizens who use the platform.

About 60% of TikTok’s 26.5 million monthly active users in the United States are between the ages of 16 and 24, the company said this year.

“National security experts have raised concerns about TikTok’s collection and handling of user data, including user content and communications, IP addresses, location-related data, metadata, and other sensitive personal information,” Shumer wrote.

He said he was especially concerned about Chinese laws requiring domestic companies “to support and cooperate with intelligence work controlled by the Chinese Communist Party.”

The inter-agency Committee on Foreign Investment in the United States (CFIUS) has launched a national security review of TikTok owner Beijing ByteDance Technology Co’s $1 billion acquisition of U.S. social media app Musical.ly.

U.S. lawmakers have also expressed concern that the Chinese company may censor politically sensitive content.

Schumer asked the Army to answer questions regarding any intelligence consultations it has done regarding TikTok by Dec. 6.