Senator Michael Bennet, Democrat of Colorado, called on Apple and Google on Thursday to remove TikTok from their app stores because of national security concerns, as bipartisan pressure on the Chinese-owned company escalates.

Mr. Bennet, a member of the Senate Intelligence Committee, sent the chief executives of Apple and Alphabet, Google’s parent company, a letter saying no company subject to “Chinese Communist Party dictates should have the power to accumulate such extensive data on the American people or curate content to nearly a third of our population.”

TikTok, which is owned by the Chinese internet company ByteDance, has faced questions about its data practices and whether it is transmitting information about Americans collected from its app to the Chinese authorities.

“It’s irresponsible for us to make it available the way we have, and I hope that Apple and Google will take this as an opportunity to lead in this debate,” Mr. Bennet said in a phone interview.