A day after North Korea sent a test ballistic missile over northern Japan Monday, infuriating the U.S. ally, the U.S. Missile Defense Agency tested an SM-6 missile off Kauai that it said successfully intercepted a medium-range ballistic missile target.

The Pearl Harbor-based USS John Paul Jones, a test bed for the Aegis ballistic missile defense program, detected and tracked the target missile launched from the Pacific Missile Range Facility on Kauai with its onboard AN/SPY-1 radar.

“We are working closely with the fleet to develop this important new capability, and this was a key milestone in giving our Aegis BMD ships an enhanced capability to defeat ballistic missiles in their terminal phase,” Missile Defense Agency Director Lt. Gen. Sam Greaves said in a release. “We will continue developing ballistic missile defense technologies to stay ahead of the threat as it evolves.”

Designated Flight Test Standard Missile-27 Event 2, Tuesday’s test marks the second time that an SM-6 missile has successfully intercepted a medium-range ballistic missile target, the agency said.

The Pentagon, meanwhile, said it detected and tracked a single North Korean ballistic missile launch at 4:57 p.m. Eastern time on Monday.

The initial assessment indicated the intermediate-range ballistic missile was launched in the vicinity of Sunan Air Base in North Korea and overflew the territory of northern Japan before landing in the Pacific Ocean approximately 500 nautical miles east of Japan.

“Our commitment to the defense of our allies, including the Republic of Korea and Japan, in the face of these threats, remains ironclad,” the Defense Department said in a statement. “We remain prepared to defend ourselves and our allies from any attack or provocation.”