The head of the U.S. Missile Defense Agency says the United States has improved its ability to shoot down long-range missiles.

Army Lieutenant General Patrick O’Reilly made the statement at a missile defense conference at the Pentagon’s National Defense University in regards to the missile threat posed by North Korea.

He said adjustments have been made to achieve higher confidence in the anti-missile defense system, even though the U.S. military successfully intercepted all three missiles launched during a trio of tests mimicking a North Korean missile offensive.

O’Reilly said the U.S. military’s ability to hit a specific spot on the target has improved dramatically according to the latest test.

The Pentagon conducted an anti-missile test simulating a North Korean attack in December of last year.