Last week, an executive order that President Trump signed prohibits commercial transactions with TikTok and WeChat from 45 days after the order was approved. If enforced, it could prevent U.S. app stores from offering the popular app and make advertising on the platform illegal, according to Reuters.

A new White House document reveals more details about the possible ramifications of the executive order directed at TikTok. The original order was quite ambiguous and did not specify the scope of the ban. In short, the order states that it prohibits transactions by the TikTok firm, but it does not detail the implications of the broad concept of “transaction.”

According to the report available to Reuters, President Donald Trump’s executive order prohibiting TikTok transactions shows that the U.S. government is considering shutting down key aspects of TikTok’s operations and financing. There are concerns about the security of personal data handled by the application.

The document states that “prohibited transactions,” could include, for example, agreements that now allow the app to be available in app stores, or buying advertising on TikTok, making advertising on the platform illegal.

These measures could completely cripple the funding and growth of the application in the United States. “That kills TikTok in the U.S,” James Lewis, a cyber-security expert at the Washington-based Center for Strategic and International Studies, told Reuters. “If they want to grow, these rules are a huge obstacle.”

In principle, Lewis also said that the U.S. government’s measures could do nothing to prevent users from downloading TikTok from foreign Websites.

Meanwhile, TikTok told advertisers they would continue to honor planned advertising campaigns, reimburse those they could not honor, and work with key influencers to migrate to other platforms in the event of a ban. Some advertisers told Reuters that they were developing contingency plans and considering other applications for their marketing.

President Trump has said he will give any U.S. company until Sept. 15 to buy TikTok or ban it. The Financial Times reported Thursday morning that Microsoft is seeking to buy all of TikTok’s global operations.

On Aug. 2, Microsoft wrote in an official statement: “Microsoft will move quickly to pursue discussions with TikTok’s parent company, ByteDance, in a matter of weeks, and in any event completing these discussions no later than Sept. 15, 2020. During this process, Microsoft looks forward to continuing dialogue with the United States Government, including with the President.”