Announcing the decision, White House press secretary Sarah Sanders said, “The security and integrity of the technology systems at the White House is a top priority for the Trump administration and therefore, starting next week, the use of all personal devices for both guests and staff will no longer be allowed in the West Wing.”

Sanders clarified the decision, saying: “Staff will be able to conduct business on their government-issued devices and continue working hard on behalf of the American people”. It is not known how these “goverment-issued devices” are differentiated from personal ones.

The ban on personal phones does not apply to the President, Donald Trump, a person close to the administration said, but it will apply to every top official working in the White House.

The proposal to ban all personal phones has apparently been floating around the White House for many months, but has never been introduced until now. Chief of staff John Kelly is believed...