TikTok said on Tuesday its head of US trust and safety, Eric Han, will depart the company on May 12, leaving the popular short-form video app without a key executive as it fights the threat of a ban in the United States.

TikTok, which is owned by Chinese tech company ByteDance, has already been banned from government-issued phones in countries such as Canada and Australia over concerns about whether the Chinese government can access user data or influence what people see on the popular app. It also faces calls from some US lawmakers to ban the app across the country.

TikTok has long said that it has never shared data with the Chinese government and would not do so if asked.

Han, who has been at TikTok since 2019, oversaw efforts like improving content moderation and reducing election misinformation. He ran trust and safety for the company’s US Data Security (USDS), a division that was created to store US data in the country on servers controlled by Oracle, in an effort to appease security concerns.

His upcoming departure also comes as TikTok is preparing to hold a presentation for advertisers in New York on Thursday.

The Verge first reported the news of Han’s upcoming departure.