WASHINGTON (Reuters) - U.S. Air Force B-1B Lancer bombers escorted by fighter jets flew in international airspace over waters east of North Korea on Saturday, in a show of force the Pentagon said demonstrated the range of military options available to President Donald Trump.

The flight, which was disclosed shortly before North Korea’s foreign minister was due to address the United Nations, 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.

“This mission is a demonstration of U.S. resolve and a clear message that the President has many military options to defeat any threat,” said Pentagon spokeswoman Dana White, calling North Korea’s weapons program “a grave threat.”

“We are prepared to use the full range of military capabilities to defend the U.S. homeland and our allies.”

The flight follows a week of heightened rhetoric from Washington and Pyongyang, with Trump and Kim Jong Un trading insults. Trump called the North Korean leader a “madman” on Friday, a day after Kim dubbed him a “mentally deranged U.S. dotard.”

Pyongyang conducted its sixth and largest nuclear test on Sept. 3 and has launched dozens of missiles this year as it accelerates a program aimed at enabling it to target the United States with a nuclear-tipped missile. The North has threatened to test a hydrogen bomb over the Pacific.

The Pentagon said the B-1B Lancer bombers came from Guam and the U.S. Air Force F-15C Eagle fighter escorts came from Okinawa, Japan. It said the operation showed the seriousness with which it took North Korea’s “reckless behavior.”