The Secret Service is prohibiting personal mobile devices, including tablets, cellphones, and smart watches, from entering the West Wing, a report Thursday evening said.

Secret Service personnel were notified that the devices will instead be placed in lockboxes or will be completely turned off prior to West Wing entry, amid news that White House chief of staff John Kelly's personal phone was compromised, MSNBC host Rachel Maddow reported on her evening program.

The new policy allegedly took effect Monday, and as of Friday will also apply to tour groups visiting the West Wing.

"This news does sort of send a chill down my spine in terms of American national security," she said.

The White House nor the Secret Service confirmed the content of the memo obtained by Maddow.