President Trump’s announcement that he plans to ban Chinese-owned TikTok has halted a potential acquisition of the popular app by Microsoft, with both companies waiting for more information from the U.S. government, according to several people involved in the talks. 

Late Friday, the companies were in advanced stages of negotiating a deal that could have been announced as soon as Monday. Under the deal, TikTok’s owner Bytedance would sell the U.S. operation of TikTok to Microsoft, and continue to operate the video app globally from a European headquarters. It’s unclear if the companies would share technology, such as through a licensing arrangement, or whether Microsoft would technically rebuild and fully operate TikTok on its own. One option under consideration would have seen Bytedance eventually separate its China business by listing it as a public company.