WASHINGTON -- U.S. President Donald Trump issued executive orders on Thursday banning any U.S. transactions with ByteDance, the Chinese company that owns video-sharing app TikTok, and Tencent, owner of the WeChat app, starting in 45 days.

The orders come as the Trump administration said this week it was stepping up efforts to purge “untrusted” Chinese apps from U.S. digital networks and called the Chinese-owned short-video app TikTok and messenger app WeChat “significant threats.”

The TikTok app may be used for disinformation campaigns that benefit the Chinese Communist Party, and the United States “must take aggressive action against the owners of TikTok to protect our national security,” Trump said in one order.

In the other, Trump said WeChat “automatically captures vast swaths of information from its users. This data collection threatens to allow the Chinese Communist Party access to Americans’ personal and proprietary information.”

The order would effectively ban WeChat in the United States in 45 days by barring “to the extent permitted under applicable law, any transaction that is related to WeChat by any person, or with respect to any property, subject to the jurisdiction of the United States, with Tencent Holdings Ltd.”

Trump said this week he would support the sale of TikTok’s U.S. operations to Microsoft Corp if the U.S. government got a “substantial portion” of the sales price but warned he will ban the service in the United States on Sept. 15.

Tencent and ByteDance declined to comment.