North Korean Missile Lands in Japan's Exclusive Economic Zone

Japanese prime minister calls launch "a serious threat to Japan's security."

— -- North Korea succeeded in launching a ballistic missile into Japan's exclusive economic zone for the first time on Wednesday, alarming its neighbors and further escalating tensions.

South Korea's Yonhap News Agency reported that the projectile appeared to be a Rodong-type, medium-range missile that flew about 620 miles and landed in the Sea of Japan within 200 nautical miles of Japan's shoreline, inside its exclusive economic zone.

The U.S. Pacific Command confirmed the launch, which included a second missile. "Initial indications reveal one of the missiles exploded immediately after launch, while the second was tracked over North Korea and into the Sea of Japan," the command said in a statement.

North Korea's top diplomat dealing with U.S. affairs told ABC News the kind of missile launch seen on Wednesday is a direct response to the "constant nuclear blackmails of the United States and to strengthen our nuclear deterrent forces in every way."

In the first interview given by North Korea's Foreign Ministry to a U.S. television network in more than a decade, Han Song Ryol, Pyongyang's top official dealing with the U.S., said the tests were "self-defensive actions to cope with the threat from United States."

Han told ABC News' Bob Woodruff, "It is the United States who provokes. It is the United States who has conducted that kind of launch many many times. It is the U.S. who threatens DPRK [North Korea] with missiles ... All these kinds of actions tell us the U.S. is taking hostile actions against DPRK. Our rocket and missile launches take place because that is the way to defend ourselves."

The Associated Press contributed reporting to this article.