US warships, with South Korea and Japan, train to shoot down North Korean missiles

U.S. warships from the USS Ronald Reagan Carrier Strike Group teamed up with South Korean and Japanese destroyers to practice shooting down missiles in the Sea of Japan Thursday, a show of force following multiple launches by North Korea this week.

"The exercises also demonstrate the deep strength of our trilateral relationship with Japan and the Republic of Korea, which is resolute against those who challenge regional stability," Pentagon press secretary Brig. Gen. Pat Ryder said during a press briefing Thursday.

The guided-missile cruiser USS Chancellorsville and guided-missile destroyer USS Benfold joined one South Korean vessel and two Japanese destroyers in the Sea of Japan for the exercise, according to U.S. Indo-Pacific Command.

"Chancellorsville provided air defense to the units as they conducted the ballistic missile exercise, which includes, detecting, tracking, and intercepting simulated targets, as well as coordination, communication, and information-sharing between the three countries," a statement from the command said. The simulation did not involve firing live rounds, a U.S. official told ABC News.

The USS Reagan and the ships belonging to its strike group had recently departed the Sea of Japan after an earlier series of drills with South Korean and Japanese naval forces. It was was operating to the east in the Pacific Ocean on Tuesday when North Korea launched a ballistic missile over Japan. In response, the strike group turned around, arriving back in the Sea of Japan on Wednesday.

That same day, North Korea launched two short-range ballistic missiles into the sea. Ryder condemned the latest launches.

"As you're aware, North Korea conducted another ballistic missile launch last night, launching two short range missiles," he said. "The United States strongly condemns this irresponsible act."

Before the anti-missile drills at sea, the U.S. responded to North Korea firing over Japan with shows of force in the air and on land alongside its allies. American fighters flew alongside Japanese and South Korean fighters, some striking ground targets on an uninhabited island west of the peninsula.

But a joint ground-to-ground missile exercise Wednesday sent mixed signals when one South Korean projectile failed soon after launch, hitting a building on its own airbase.

The South Korean joint chiefs of staff said one of its Hyunmoo missiles "fell after an abnormal flight" in Gangneung, which is along the northeast coast of the country, adding that there were no casualties reported, and the cause was being assessed.

Meanwhile, officials warn that North Korea could soon conduct its first nuclear test since 2017.

The U.S. still assesses North Korea is making preparations for such a test, but is not sure when, according to Ryder.

"If and when they do conduct a nuclear test, I'm not going to speculate," Ryder said.