U.S. Air Force B-1B Lancer bombers escorted by fighter jets flew in international airspace over waters east of North Korea on September 23.
The flight was the farthest north of the demilitarized zone separating North and South Korea that any U.S. fighter jet or bomber has flown in the 21st century, the Pentagon said.
Tensions have been on the rise recently over the North's nuclear tests.
The flight was announced shortly before North Korea's Foreign Minister Ri Yong Ho told the UN General Assembly in New York that U.S. President Donald Trump was on a "suicide mission."
Ri said Trump's vow to "totally destroy" his country if necessary had made "our rockets' visit to the entire U.S. mainland all the more inevitable."
Referring to Trump as a "mentally deranged person full of megalomania," Ri said the U.S. president posed "the gravest threat to international peace and security today."
In his first address to the General Assembly on September 19, Trump called leader Kim Jong Un a "Rocket Man" on a "suicide mission."
Ri said Trump was turning the United Nations into a "gangsters' nest where money is respected and bloodshed is the order of the day," and accused him of insulting Kim.
"None other than Trump himself is on a suicide mission," he said.
Shortly before Ri's address, Pentagon spokeswoman Dana White said, "This mission is a demonstration of U.S. resolve and a clear message that...President [Trump] has many military options to defeat any threat."
"We are prepared to use the full range of military capabilities to defend the U.S. homeland and our allies," White said.
The Pentagon said the B-1B Lancer bombers came from the U.S. Pacific territory of Guam. The U.S. Air Force F-15C Eagle fighter escorts came from Okinawa, Japan.
The flight comes after a week of heated rhetoric between the two leaders. After Trump's comments, Kim called him "mentally deranged" and "a dotard."
North Korea conducted its sixth and largest nuclear test on Sepember 3, has launched dozens of missiles this year, and has threatened to test a hydrogen bomb over the Pacific Ocean.