Two U.S. senators say the time has come for an investigation into TikTok. The senators have requested that U.S. intelligence officials examine the wildly popular, Chinese-owned social media app for potential "national security risks."

"With over 110 million downloads in the U.S. alone, TikTok is a potential counterintelligence threat we cannot ignore," Senate Minority Leader Chuck Schumer, a Democrat from New York, and Republican Senator Tom Cotton of Arkansas wrote in a letter Wednesday to Director of National Intelligence Joseph Maguire.

"Given these concerns, we ask that the Intelligence Community conduct an assessment of the national security risks posed by TikTok and other China-based content platforms operating in the U.S. and brief Congress on these findings," the letter says.

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The Washington Post first reported on the letter.

TikTok, which is owned by the Beijing-based tech company ByteDance, launched in 2016, and has been downloaded more than 1 billion times worldwide, according to the app tracker Sensor Tower. TikTok lets users create short, looping clips — usually music, dance or comedy videos. The app spawned an entire industry of viral stars and influencers, and it is even used by several Democratic presidential candidates and major U.S. news organizations.

TikTok's policies say the app collects user data such as IP addresses, location and information about devices. The app is not available in China, and the company says data from American users is kept in the U.S.

But since it is owned by a Chinese company, TikTok would still have to comply with Chinese laws, which say companies must support intelligence work by the country's ruling Communist Party.

Schumer and Cotton point out that ByteDance uses its platforms, including TikTok, "as part of an artificial intelligence company powered by algorithms that 'learn' each user's interests and preferences through repeat interaction."

TikTok settled a case with the U.S. Federal Trade Commission for $5.7 billion for collecting data on child users without parental consent, back when the app was called Musical.ly. It was the largest civil penalty the agency ever collected for a children's data-privacy case.

In a statement replying to the senators' letter, TikTok denied that it improperly stores U.S. data or allows its content to be influenced by the Chinese government. It said that a team of American moderators based in California reviews content in accordance with U.S. policies.

"We look forward to continued engagement on these and other issues to show that TikTok is dedicated to providing a trusted platform for entertainment and creativity," the statement says.

The senators point to reports that TikTok censors content that is critical of China, such as videos about the recent Hong Kong protests. ISIS militants have also used TikTok for recruitment and spreading graphic propaganda videos. TikTok announced this week that it had taken down about two dozen ISIS-affiliated accounts.

The senators also say TikTok could become a target for foreign influence campaigns, such as the ones that targeted the 2016 presidential election.

The letter comes months after the Trump administration blacklisted U.S. business with Huawei, a Chinese telecommunications giant. The administration cited Huawei's ties to the Chinese government, and fear that the company's technology could be used to spy on Americans — something Huawei denies.

This is the second time in the past month that senators called for a federal probe of TikTok and ByteDance. Senator Marco Rubio, a Republican from Florida, said the app should be investigated for censoring content that could upset the Chinese government.