Kevin Mayer, the chief executive of TikTok, has accused Facebook of trying to destroy the Chinese app’s US business by smearing it with “maligning attacks.”

In his first public comments since joining TikTok from Disney, Mr. Mayer issued an 800-word defense of the viral video app, which is under pressure from US regulators and may even be banned by the White House.

Without TikTok, he said, American advertisers “would again be left with few choices”. He described Instagram Reels, a new video service from Facebook that will launch in the US in early August, as a “copycat product” and noted that a similar service from Facebook called Lasso had “failed quickly”.