Incredible photo of a North Korean soldier covertly photographing Rex Tillerson

During his visit to a UN base on the border of North and South Korea on Friday, Secretary of State Rex Tillerson was photographed by a Reuters photographer and also, seemingly unwittingly, by a North Korean soldier.

In the right hand corner of the photo, a North Korean soldier is visible peering in through a window and photographing Tillerson and a US Army general from behind. 

The photo was taken in the truce village of Panmunjom inside the Demilitarized Zone, which was created after the Korean War on what is now the most heavily armed border in the world. 

The window photographer is perhaps a symbol of the notorious surveillance state the North Korean dictatorship has long maintained. 

Last year, the country conducted two nuclear test explosions and 24 ballistic-missile tests, violating UN Security Council resolutions and international sanctions and marking an acceleration in its nuclear weapons development. Experts believe North Korea may have a nuclear weapon that could reach the US in the next few years.

On Friday, Tillerson announced that the US may take preemptive military action against North Korea if the threat from its nuclear weapons program rises to a level "that we believe requires action." He told reporters at a Friday news conference in Seoul that "all of the options are on the table."

NBC reporter Brad Jaffy tweeted a zoomed-in version of the photo: