Senators Tom Cotton and Pete Ricketts said "there's no legal basis" for an extension to keep the social media platform online.

The president-elect Sunday pledged an executive order, hours into his second term, returning access for American users, at least temporarily.

The federal ban on TikTok took effect Sunday, but President-elect Donald Trump has indicated he will probably reinstate the app when he returns to office a day later—though he may have limited options to stave off a ban, and any attempts to stop it could be challenged in court. (Follow live updates on the TikTok ban here.)