North Korea says it has successfully tested an ICBM?

“That range would not be enough to reach the lower 48 states or the large islands of Hawaii, but would allow it to reach all of Alaska”

North Korea said on Tuesday that it had successfully conducted its first test of an intercontinental ballistic missile, claiming a milestone in its efforts to build nuclear weapons capable of hitting the mainland United States.

Tuesday’s launch was the first missile test since President Trump and his South Korean counterpart, Moon Jae-in, agreed to put more pressure on the country to come to the negotiating table.

The missile took off from the Banghyon airfield in the northwestern town of Kusong and flew 578 miles before landing in the sea between North Korea and Japan, the South Korean military said in a statement. Military officials were still analyzing flight data to determine what type of missile had been used.

It was the first missile test by the North since it launched land-to-sea cruise missiles off its east coast on June 8. Under a series of United Nations Security Council resolutions, North Korea is prohibited from developing or testing ballistic missiles.

The Japanese government said the missile landed in its so-called exclusive economic zone off its western coast. The United States Pacific Command said it had tracked the intermediate-range missile for 37 minutes. In Seoul, Mr. Moon, who during his election campaign this year advocated talks with the North, met with senior security officials to discuss the latest provocation, his office said.

While the North is believed to have made significant progress in its weapons programs, experts believe it still has a long way to go in miniaturizing nuclear warheads for intercontinental ballistic missiles.

After their initial assessment that the North Korean projectile was an intermediate-range missile, the United States and South Korean authorities were continuing to analyze the data “with the possibility that it was actually an ICBM-class missile,” said Mr. Moon, the South Korean president.

If the missile took 37 minutes to fly 580 miles, as the South Korean and United States military analysts said, that would mean that it had a highly lofted trajectory, probably reaching an altitude of more than 1,700 miles, said David Wright, co-director of the Global Security Program at the Union of Concerned Scientists.

Such a missile would have a maximum range of roughly 4,160 miles, or 6,700 kilometers, on a standard trajectory, he said.

“That range would not be enough to reach the lower 48 states or the large islands of Hawaii, but would allow it to reach all of Alaska,” Mr. Wright wrote in a blog post.

The missile looked like the longest-range missile that North Korea had ever tested, and its long flight time was “more consistent with an ICBM that can target Alaska and perhaps Hawaii,” said Jeffrey Lewis, director of the East Asia Nonproliferation Program at the Middlebury Institute of International Studies.

“It’s a very big deal — it looks like North Korea tested an ICBM,” he said by email. “Even if this is a 7,000-km-range missile, a 10,000-km-range missile that can hit New York isn’t far off.”

But analysts also cautioned that although they have been impressed by the rapid and steady progress in the North’s missile programs, the long flight time itself did not suggest that North Korea had mastered the complex technologies needed to build a reliable nuclear-tipped ICBM, such as the know-how to separate the nuclear warhead and guide it to its target.