Secretary of State Rex W. Tillerson had also cited a pause in testing by the North, saying he was “pleased to see that the regime in Pyongyang has certainly demonstrated some level of restraint that we have not seen in the past.” Mr. Tillerson suggested that it could be a “pathway” to dialogue.
Only days later, that optimism seemed premature when the North Koreans launched three short-range missiles on Saturday. Two of them traveled about 155 miles before splashing down, far enough to reach major South Korean and American military bases, including those about 60 miles south of Seoul.
And while North Korea has not carried out its threat to fire missiles toward the coast of Guam — and near an American air base — the missile it fired over Japan on Tuesday appeared to be of the same type: An intermediate-range missile that could target American, South Korean and Japanese bases in northeast Asia.
Only twice before has the North fired projectiles over Japanese territory: Once in 1998, prompting a minor diplomatic crisis in Asia, and once again at the beginning of the Obama administration in 2009. In both those cases, the North said the rockets were carrying satellites into orbit. In this case, it made no such claim.
As in the case of the 2009 launch, which was paired with a nuclear-weapons test, North Korea appears to be testing a new American president.
Notably, the missile fired on Tuesday took off from near Pyongyang, the North Korean capital. Early reports, which are often later corrected, indicated that it was launched from near Pyongyang’s international airport, not the usual launch site in the country’s northeast, according to the South Korean military. They said they were still trying to determine what type of missile was launched.
American officials noted that if it was in fact launched from the outskirts of the capital, it may have been designed to complicate recent American threats to hit the North with pre-emptive strikes. That possibility was explicitly raised this month by several Trump administration officials, as a way of seeking to deter the North Koreans.
While the North’s usual launch sites are in remote areas, where there would be little concern about civilian casualties, any strike near Pyongyang would risk many civilian deaths and would suggest the real goal was to strike at the regime.
An attack near Pyongyang would also be far more likely to result in North Korean retaliation against Seoul.
Lt. Gen. Hiroaki Maehara, commander of Japan’s Air Self Defense Force, said that Japan did not attempt to shoot down the missile from North Korea on Tuesday because the government did not detect a threat to Japanese territory.
But when its surveillance first detected the launch and followed the path of the missile, it warned its citizens in the path of the missile to take cover — just in case any parts fell on Japan.
The North Korean missile tests on Saturday and again on Tuesday came during joint military drills that the United States and South Korea started a week ago. For the United States and South Korea, these drills — mostly conducted on computer screens — are normal exercises. But the North calls such annual drills a rehearsal for invasion and often lashes out with weapons trials and military exercises of its own.
But in this case, it was Japan — not part of this exercise — that seemed most directly affected.
In a statement, Mr. Abe said his government “was prepared to take all the measures to protect people’s lives.”
“We have lodged a firm protest to North Korea. We have requested an urgent meeting of the U.N. Security Council,” he added.
The Japanese government sent a text alert to citizens about the launch and advised them to take protective cover. In a post on Mr. Abe’s Twitter account, the government confirmed that the missile was fired at 5:58 a.m. local time, before breaking into three pieces and landing about 730 miles off the coast of Cape Erimo, Hokkaido, around 6:12 a.m.
This month, North Korea had threatened to launch four of its Hwasong-12 intermediate-range ballistic missiles in a “historic enveloping fire” around Guam, home to major American Air Force and Navy bases. The North said the missiles would fly over southern Japanese provinces on their way toward Guam.
That threat, together with Mr. Trump’s warning that the United States would bring down “fire and fury” if the North didn’t stand down, has significantly raised tensions in the region.
But the anxiety had appeared to ease somewhat after the North Korean leader later said he would wait awhile, watching the United States behavior, before deciding whether to approve his military’s plan to launch missiles toward Guam. The missile fired on Tuesday took a different path over northern Japan.
Still, the missile tests in recent days have dashed hopes in Seoul and Washington that North Korea would restrain from weapons tests to help pave the way for possible dialogue.
North Korea has conducted more than 80 missile tests since Mr. Kim came to power in late 2011, after the death of his father, but it has not sent any of those missiles over Japan.
Even when it flight-tested an intercontinental ballistic missile on July 28, it was launched at a highly lofted angle so that the missile reached an altitude of 2,300 miles. But it flew only 998 horizontal miles, falling in waters between the North and Japan. The North said at the time that it did so in order not to send its missile over a neighbor. Thus, the missile test on Tuesday was considered an especially bold move.
Along with South Korea, Japan and Guam would likely be the first targets of a North Korean attack should war break out on the Korean Peninsula, analysts said. Both are home to major American military bases, which will become key launching pads for American forces in the event of war in Korea.