TikTok’s interim CEO, Vanessa Pappas, is asking Facebook and Instagram to “publicly join our challenge and support our litigation,” as TikTok faces a new executive order from the Trump administration that will block people from downloading the app beginning September 20th.

The new order was issued by the Department of Commerce on Friday morning, and it essentially states that people aren’t allowed to download TikTok or WeChat beginning on the 20th. TikTok will continue to work in the United States for people who already have the app installed, but future downloads are prohibited.

Pappas’ call to action came in the form of a reply to a tweet by Adam Mosseri, the head of Instagram, who said that a “US TikTok ban would be quite bad for Instagram, Facebook, and the internet more broadly.” Pappas added that it’s a moment “to put aside our competition and focus on core principles like freedom of expression and due process of law.” Pappas’ prompt comes at a time when rumors are swirling that Instagram co-founder Kevin Systrom is in talks to replace recently departed TikTok CEO Kevin Mayer.

The Trump administration called for a TikTok ban earlier this year due to data security concerns. The administration demanded that ByteDance sell its US operations to an American company by September 15th or TikTok would be banned entirely. Currently, the administration and ByteDance are reportedly working with Oracle to secure a deal. TikTok also filed a lawsuit against President Trump in August, arguing that Trump’s original order offers no evidence that TikTok is indeed a national security threat to the United States, among other things.

TikTok issued a statement following the Department of Commerce’s order, noting that the company has already “committed to unprecedented levels of additional transparency and accountability well beyond what other apps are willing to do.” The statement adds that TikTok is already planning to work with an American tech provider, which would “be responsible for maintaining and operating the TikTok network in the US, which would include all services and data serving US consumers.”

“We will continue to challenge the unjust executive order, which was enacted without due process and threatens to deprive the American people and small businesses across the US of a significant platform for both a voice and livelihoods.”