President Donald Trump on Thursday ordered a sweeping but unspecified ban on dealings with the Chinese owners of consumer apps TikTok and WeChat, although it remains unclear if he has the legal authority to actually ban the apps from the United States. The twin executive orders — one for each app — take effect in 45 days. They call on the Commerce Secretary to define the banned dealings by that time. While the wording of the orders is vague, some experts said it appears intended to bar the popular apps from the Apple and Google app stores, which could effectively remove them from distribution in the US. “This is an unprecedented use of presidential authority,” Eurasia Group analyst Paul Triolo said. At a minimum, he said, the orders appear to “constitute a ban on the ability of US app stores run by Apple and Google to include either mobile app after 45 days”. Mr Triolo said the orders may face legal challenges and warned that Beijing was likely to “react harshly, at least rhetorically”. Mr Trump’s orders cited legal authority from the International Emergency Economic Powers Act and the National Emergencies Act. The Trump administration has railed against the threat from China, and both Republican and Democratic legislators have also raised concerns about TikTok, including censorship, misinformation campaigns, the safety of user data and children’s privacy. But the administration has provided no specific evidence that TikTok has made US users’ data available to the Chinese government. Instead, officials point to the hypothetical threat that lies in the Chinese government’s ability to demand co-operation from Chinese companies. Earlier in the week, Mr Trump threatened a deadline of September 15 to “close down” TikTok unless Microsoft or another company acquires it. On Wednesday, US Secretary of State Mike Pompeo announced an expansion of the US crackdown on Chinese technology to include barring Chinese apps from US app stores, citing alleged security threats and calling out TikTok and WeChat by name. TikTok and Microsoft had no immediate replies to queries. Tencent, the owner of WeChat, declined to comment. Tencent shares plunged as much as 10 per cent in morning trade in Hong Kong on Friday before paring losses and ending the session down 6.75 per cent at HK$518.00, dragging the broader Hang Seng Index down more than 2 per cent. Leading mobile security experts say TikTok is no more intrusive in its harvesting of user data and monitoring of user activity than US apps owned by Facebook and Google. “I am the first to yell from the rooftops when there is a glaring privacy issue somewhere. But we just have not found anything we could call a smoking gun in TikTok,” mobile security expert Will Strafach told The Associated Press last month after examining the app. Mr Strafach is chief executive of Guardian, which provides a firewall for Apple devices. The order does not seem to ban Americans from using TikTok, said Kirsten Martin, a professor of technology ethics at the University of Notre Dame. She added that such an order would be nearly impossible to enforce in the first place. “If the goal is to get teenagers to stop using TikTok, I’m not sure an executive order will stop them,” she said. “Every teenager knows how to use a VPN (a virtual private network). They will just pretend they are in Canada.” TikTok is a video-sharing app that is widely popular among young people in the US and elsewhere. It is owned by the Chinese company ByteDance, which operates a separate version for the Chinese market. TikTok insists it does not store US user information in China and would not share it with the Chinese government. TikTok says it has 100 million US users and hundreds of millions globally. According to research firm App Annie, TikTok had 50 million weekly active users in the US during the week of July 19, the latest available figure – 75 per cent more than in the first week of the year. WeChat and its sister app Weixin in China are hugely popular messaging apps; many Chinese expatriates use WeChat to stay in touch with friends and family back home. WeChat also says it does not share data with the Chinese government and never has, and does not store international user data in China. US user data is stored in Canada. The order against Tencent could have ramifications for users beyond WeChat, which is crucial for personal communications and organisations that do business with China. Tencent also owns parts or all of major game companies such as Epic Games, publisher of Fortnite, a major video game hit, and Riot Games, which is behind League of Legends.