WASHINGTON — The Pentagon’s oft-criticized missile defense program has scored a triumph, destroying a mock warhead over the Pacific Ocean with an interceptor that is key to protecting U.S. territory from a North Korean attack.

Vice Adm. Jim Syring, director of the Pentagon agency in charge of developing the missile defense system, called Tuesday’s test result “an incredible accomplishment” and a critical milestone for a program hampered by setbacks over the years.

“This system is vitally important to the defense of our homeland, and this test demonstrates that we have a capable, credible deterrent against a very real threat,” Syring said in a written statement announcing the test result.

Despite the success, the $244 million test didn’t confirm that under wartime conditions the U.S. could intercept an intercontinental-range missile fired by North Korea. Pyongyang is understood to be moving closer to the capability of putting a nuclear warhead on such an ICBM and could develop decoys sophisticated enough to trick an interceptor into missing the real warhead.