Embattled social media platform TikTok said Friday that General Counsel Erich Andersen has stepped down to focus on the company’s fight against a new federal law that will ban the app in the United States if its Chinese owner doesn’t sell its stake within a year.

Andersen, who is based in the United States and is a former deputy general counsel at Microsoft, said in a statement that it was a “difficult decision” to step down from a role he’s held for four years.