The planes took off from Okinawa, Japan and flew over the waters east of the Korean Peninsula.
“This is the farthest north of the Demilitarized Zone (DMZ) any U.S. fighter or bomber aircraft have flown off North Korea’s coast in the 21st century, underscoring the seriousness with which we take (North Korea’s) reckless behavior,” said Pentagon spokeswoman Dana White.
— U.S. Pacific Command (@PacificCommand) September 23, 2017
The DMZ is a strip of land running across the Korean Peninsula near the 38th Parallel, separating North Korea from South Korea. It was created in 1953, following the armistice which ended the Korean War.