SEOUL, South Korea – Along the demilitarized zone that separates North and South Korea, little has changed between the soldiers manning both sides of the iconic border, even if the international rhetoric around them has changed substantially.

“We still pass messages,” said one U.S. Forces-Korea official who spoke on the condition of not being identified, referring to the way that North and South Korea have kept a line of communication open, not only in this most recent time of tension, but also in previous decades.

It’s one of the odd qualities of the highly symbolic DMZ, which has elements in place to try and maintain the peace between North Korea and South Korea, even as both sides seem to edge toward conflict. While the Joint Security Area at the DMZ and its famous blue meeting houses doubles as a stopping point for educational tours and can be a place for family reunification, it’s also a sensitive military checkpoint, one that President Donald Trump has said he will not visit during his stop in Seoul on Tuesday.

It’s also previously been the scene of successful communication between the two sides, even after highly publicized security incidents.

“There’s a way to talk on the phone, there’s a way to pass a message over bullhorn and then there’s the buildings there, the blue buildings, one, two and three, to actually come into those meeting rooms. The 05-level [Lt. Col to Lt. Col-level) talks that happened earlier this year happened in one of the blue buildings,” the official said in late October to reporters traveling with Joint Chiefs chairman Gen. Joseph Dunford in South Korea. In the blue meeting house visit this year, officials from North Korea and South Korea met in order to resolve the repatriation of some remains.

In recent years, the two governments have been able to successfully resolve getting lost fishermen home, returning remains found in the water and repatriating remains from the Korean War, the official said, despite previous escalations.