SEOUL - North Korea said on Friday that it had successfully tested a new solid-fuel intercontinental ballistic missile, which can be deployed more quickly than previous versions, giving potential targets - including the United States - less time to spot and respond to any incoming rocket.

North Korea's claims of a "breakthrough" have not been independently assessed, and South Korea's defense ministry said its neighbor needed more time to develop a reliable solid-fueled projectile. Yet, the claim underlines Pyongyang's determination to press ahead with its nuclear weapons program.

North Korean leader Kim Jong Un oversaw Thursday's test, which he said demonstrates "our ever-increasing defense technological might," according to a report on North Korea's Central News Agency on Friday.

North Korea's neighbors detected the missile soon after it launched and condemned it as a dangerous provocation, triggering an evacuation order on Japan's northern Hokkaido island. The missile landed outside Japan's exclusive economic zone, far from land.

The new long-range weapon, named "Hwasong-18," shows "the emergence of another powerful nuclear attack means of the DPRK and demonstrate the reliable nuclear war deterrence of the state," the state news agency said, using the abbreviation for the country's official name.

This is North Korea's first official test of a long-range missile powered by solid fuel, which involves fewer preparation steps than a liquid-propelled one and can therefore be launched more quickly.

"It considerably shortens the window of opportunity for South Korea and the U.S. to detect and intercept the missile," said Cheon Seong-whun, a former national-security official in Seoul. South Korea's "Kill Chain" preemptive strike capability could be "rendered powerless" by this new North Korean development, he said.

The North Korean leader expressed "great satisfaction" over the test and said it will bring "extreme uneasiness and horror" to the enemies. State media photos showed Kim smiling with his daughter Kim Ju Ae at the test site. The young girl's repeated appearances at key military events demonstrate Kim's nuclear ambitions for the future generation, experts say.

The solid-fuel ICBM adds to Kim's nuclear arsenal, which it has been expanding under a five-year defense plan laid out in 2021. North Korea has since geared up its weapons activity to an unprecedented level, testing a variety of cruise, ballistic and hypersonic missiles.

North Korea justifies its military pursuits as a countermeasure to joint military exercises between South Korea and the United States, which have been scaled up in recent months.

The latest missile launch comes amid an ongoing blockade in the communication hotline between rival Koreas. Seoul last week criticized North Korea's "irresponsible" silence and urged Pyongyang to respond to routine calls.

On Friday, South Korea's Defense Ministry downplayed the North's alleged missile development as "short of completion." "We have a more effective and state-of-art solid-fuel ballistic missile technology [than North Korea]," the ministry said.

In February, North Korea showed off its largest array of long-range missiles in a fanfare-filled parade in the capital. State media claimed the weapons on display demonstrated the country's "greatest nuclear strike capability."

American intelligence officials concluded that the parade "probably oversells" the missiles' capacity to strike the United States, according to a classified Pentagon document leaked as part of a trove that surfaced on social media earlier this month and has been obtained by The Washington Post.

The weapons showcased at the parade were "nonoperational systems to portray a larger, more capable missile force than it possesses and to mitigate the risk of damage to its real missiles," the document said.

The document cited "testing hurdles and resource constraints" as what would limit North Korea from actually operating the weapons systems displayed.