ByteDance is building a stand-alone version of TikTok for the United States that will run on its own algorithm and store only American user data, according to internal documents and employees cited by Reuters. The initiative, code-named “M2,” aims to transfer and duplicate the short-video app’s codebase before a planned launch in early September. Users outside the U.S. will not see the new app in their stores, and the current TikTok application would be removed when the replacement goes live, with a grace period for existing downloads that could last until March 2026. Engineering teams have been working under tight deadlines to finish the separation, which affects some 170 million U.S. users and is the most extensive technical split TikTok has attempted since its global rollout. The company says the new build will train recommendation models solely on U.S. data, mirroring the domestic-only structure of Douyin in mainland China. The change is intended to address Washington’s long-standing national-security concerns that Beijing could gain access to American data or manipulate content. The redesign comes as the Trump administration presses ByteDance to divest TikTok’s U.S. operations by 17 September or face a nationwide ban mandated by a 2024 law. Commerce Secretary Howard Lutnick told CNBC that the video service “will go dark” unless China approves a sale that puts its algorithm and majority ownership under American control. “You can’t have Chinese control and have something on 100 million American phones,” he said. People familiar with the talks say the leading proposal would move TikTok U.S. into a new joint venture majority-owned by investors such as Susquehanna International Group, General Atlantic, KKR, Blackstone and Andreessen Horowitz, with Oracle expected to take a stake and ByteDance retaining a minority interest. Beijing’s permission is uncertain: China’s updated export-control rules give it a veto over transferring recommendation algorithms, the asset Washington most wants to localize. Until a resolution emerges, TikTok is racing to finish its U.S.-only app as both sides edge toward the September deadline.