North Korea ignored U.N. resolutions by firing a medium-range ballistic missile into the sea on Friday, Seoul and Washington officials said, days after its leader Kim Jong Un ordered weapons tests linked to its pursuit of a long-range nuclear missile capable of reaching the U.S. mainland.

South Korea’s Joint Chiefs of Staff said in a statement that the missile fired from a site north of Pyongyang flew about 800 kilometers (500 miles) before crashing off the North’s east coast. It was the first medium-range missile launched by the North since it fired two in April 2014, said a South Korean defense official, requesting anonymity citing department rules.

A senior U.S. defense official said the missile appeared to be a Rodong type fired from a road-mobile launcher. The test violated multiple U.N. Security Council resolutions that ban North Korea from engaging in any ballistic and nuclear activities, said the official, speaking on condition of anonymity because he was not authorized to discuss the matter publicly.

The launch came as North Korea condemned ongoing annual South Korean-U.S. military drills that it sees as an invasion rehearsal. The two sets of drills are the largest ever, in response to the North’s nuclear test and long-range rocket launch earlier this year. One of the drills, computer-simulated war games, was to end later Friday while the other, field training, is to continue late April.

In recent weeks, North Korea threatened pre-emptive nuclear strikes against Washington and Seoul and fired short-range missiles and artillery into the sea in an apparent anger over the drills and tough U.N. sanctions imposed over its nuclear test and rocket launch.

South Korea’s military said its surveillance equipment detected the trajectory of a suspected second missile fired from the same site. A Joint Chiefs of Staff statement said the object later disappeared from South Korean radar at an altitude of 17 kilometers (10 miles) and that it was trying to find out if a missile had been fired or something else was captured by the radar.

No fresh sanctions on the North were expected for Friday’s launch. The U.N. Security Council slapped the country with sanctions each time when it conducted nuclear tests and long-range rocket launches, but it usually responded to short- and medium-range ballistic launches with statements criticizing them.

On Tuesday, North Korea’s state media said Kim had ordered tests soon of a nuclear warhead and ballistic missiles capable of carrying warheads. Kim issued the order while overseeing a successful simulated test of a re-entry vehicle aimed at returning a nuclear warhead into the atmosphere from space so it could hit its intended target, according to the North’s Korean Central News Agency.

Taewoo Kim, a military expert at the South’s Konyang University, said it is likely that Friday’s launch was a test of a re-entry vehicle mounted on the purported Rodong missile.

The North Korean missile fired may not be a Rodong but a long-range missile whose launch angle was altered so that it didn’t fly its full range, said Kwon Sejin, a professor at the Korea Advanced Institute of Science and Technology in South Korea. He said the missile may have carried an empty warhead, which contains trigger devices but lack plutonium or uranium, to see if it can survive the fiery re-entry and detonate at the right time.

Outside experts said it is a key remaining technology that North Korea must master to achieve its goal of developing a long-range missile capable of hitting the U.S. mainland. South Korean defense officials said earlier this week that North Korea had yet to develop the re-entry technology, so it still does not have a functioning intercontinental ballistic missile.

The South Korean defense official said Seoul has no immediate plans to try to retrieve debris of the missile that appeared to have landed in the waters inside Japan’s air defense identification zone. South Korea did not retrieve missile parts after the North’s 2014 launches either.

North Korea is thought to have a small arsenal of atomic bombs, but South Korean officials and many outside experts say they are not small enough to place on missiles that can strike faraway targets.

Analyst Lee Choon Geun at South Korea’s state-funded Science and Technology Policy Institute said the North can probably place nuclear warheads on its shorter-range Scuds and medium-range Rodong missiles, which would put South Korea and Japan under its striking range. Other analysts question that.

The North began to develop ballistic missiles in the 1970s by reverse-engineering Soviet-made Scuds it acquired from Egypt. After several failures it put its first satellite into space aboard a long-range rocket launched in December 2012. Its second successful satellite launch occurred this February. The U.N., the U.S. and others say the launches were a banned test of missile technology. Ballistic missiles and rockets used for satellite launches share similar bodies, engines and other technology.

(AP)