A US judge has blocked an attempt by President Donald Trump to ban the Chinese messaging app WeChat, saying it raised serious questions about free speech, protected under the constitution’s first amendment.

The US Department of Commerce was due to implement a ban on WeChat appearing in US app stores on Sunday.

But a group of WeChat users challenged an executive order signed by Mr Trump that would have shut down the app in the country.

The US Justice Department insisted that blocking the order would “frustrate and displace the president’s determination of how best to address threats to national security.”

Mr Trump claims the app could pass US user data to the Chinese government.

The Department of Commerce insisted that WeChat has collected “vast swathes of data from users, including network activity, location data, and browsing and search histories.”

But Judge Beeler said that “while the general evidence about the threat to national security related to China (regarding technology and mobile technology) is considerable, the specific evidence about WeChat is modest.”

Beijing says Mr Trump’s claims are baseless and WeChat owner Tencent insists that all chats on the app are private.