The Pacific Command previously said that two of the North Korean missiles had “failed in flight.” But that assessment was later retracted, and the amended view agreed with the South Korean military’s evaluation of the distance the projectiles had traveled.
The three missiles were 300-millimeter rockets fired from a multiple-tube launcher, said Yoon Young-chan, a spokesman at the Blue House, South Korea’s presidential office, where the country’s National Security Council met on Saturday to discuss the tests.
North Korea has alarmed South Korean defense officials before with tests of its 300-millimeter rockets and displays of an eight-tube version of the system during military parades. The officials say the North has developed the multiple-tube launchers because they are cheaper than short-range, Scud-type ballistic missiles and because they enable more projectiles to be fired.
North Korea keeps thousands of rocket launchers, as well as long-range artillery pieces, along the border with the South, threatening to rain down a “sea of fire” on South Korean cities and islands near the border. The old 240-millimeter rockets have an estimated range of 37 miles, putting Seoul, a capital with 10 million people, within reach.
Kim Dong-yub, a defense analyst at the Institute for Far Eastern Studies at Kyungnam University in Seoul, said the tests on Saturday appeared to be aimed at expanding the strike range.
Nevertheless, the nature of the tests prompted some relief in the region.
The missiles flew to the northeast, not toward Guam, home to major United States Air Force and Navy bases. North Korea threatened to launch ballistic missiles in a “ring of fire” around Guam after President Trump threatened to hit the North with “fire and fury” if it persisted with its development of ICBMs.
South Korea did not issue its usual condemnatory statement against the tests. In Tokyo, the chief cabinet secretary, Yoshihide Suga, said the missiles did not fall in Japanese waters or pose a threat to his nation’s safety. White House officials said that Mr. Trump had been briefed on the tests but did not immediately have any further comment.
Secretary of State Rex W. Tillerson this past week credited the North with showing some restraint by not launching a missile since the ICBM test in July, and he had expressed hope that the easing of tension could lead to dialogue.
The North’s latest tests appeared to be a response to the joint military drills that the United States and South Korea started on Monday. The North calls such annual drills a rehearsal for invasion and often lashes out with weapons tests and military exercises of its own.
North Korea’s state media reported on Saturday that the country’s leader, Kim Jong-un, had guided an amphibious landing and aerial strike exercise by his military, which involved multiple-rocket launchers and targets modeled after South Korean islands near the sea border. In 2010, the North launched a deadly artillery attack on a South Korean island.
Mr. Kim also visited a weapons development institute in the past week. Photographs published in the North’s state media from that visit suggested that North Korea was developing new missiles. They also seemed to show that the country was using special fiber to build lighter-weight composite rocket casings.