Updated at 7:19 p.m. ET
Secretary of State Rex Tillerson confirmed Tuesday that the missile launched by North Korea on Monday was an intercontinental ballistic missile, in a statement in which he condemned the test.
"Testing an ICBM represents a new escalation of the threat to the United States, our allies and partners, the region, and the world," Tillerson said.
In response to the test, U.S. and South Korean forces conducted joint military exercises aimed at "countering North Korea's destabilizing and unlawful actions on July 4," according to a statement issued by the U.S. Army.
The exercise, off the east coast of South Korea, deployed rockets from both the U.S. and South Korean missile arsenals, the statement said.
It added: "The U.S. commitment to the defense of the ROK (Republic of Korea) in the face of threats is ironclad."
In an earlier joint statement, China and Russia called the test "unacceptable" and called for a moratorium on nuclear and missile tests by North Korea — and a suspension of large-scale military exercises by the U.S. and South Korea. The Associated Press has more:
"The foreign ministries said that as a 'voluntary political decision,' North Korea should declare a 'moratorium on testing nuclear devices and test launches of ballistic missiles.' In turn, the U.S. and South Korea should 'accordingly refrain from large-scale joint maneuvers,' the joint statement added.
"They said 'the confronting parties' involved should sit down for talks to agree on principles that include a refusal to use force and a pledge to make the Korean Peninsula free of nuclear weapons."
Our previous post continues below:
North Korea says it has successfully tested an intercontinental ballistic missile, which in theory, can fly far enough to reach Alaska.
North Korean state TV broke in with the announcement with a triumphant anchor declaring, "Our intercontinental ballistic rocket can reach anywhere in this world, and we can end America's nuclear threat and bring peace to the Korean peninsula."
If confirmed, this would mark the first successful test of a North Korean missile capable of reaching the United States — a longstanding goal for Pyongyang. It's not clear whether North Korea would have the ability to put a nuclear warhead on the missile, a separate technical challenge.
In its initial analysis, the U.S. Pacific Command said it had detected and tracked the launch of an intermediate-range missile, which would have a much shorter range than what North Korea is claiming.
South Korea's and Japan's militaries analyzed the flight and say the missile flew nearly 600 miles, reaching an altitude of 1,500 miles — higher than many satellites in orbit — before turning to come back down. It flew for an estimated 40 minutes before landing in the Sea of Japan and within Japan's exclusive economic zone.
If the missile were traveling forward instead of upward, in a flatter trajectory, it's estimated it would have a range that could put Alaska at risk.
The missile flight is the 12th North Korean provocation of the year, breaking United Nations resolutions barring such tests.
"It is a serious threat to Japan's security and cannot be tolerated," Japan's Defense Ministry said.
The move by Pyongyang comes following a White House summit between President Trump and South Korean President Moon Jae-in, in which the two countries pledged to coordinate on North Korea policy and continue a security alliance that has lasted more than 60 years.
Moon assembled the country's national security team for an emergency meeting.
Trump responded to the test in tweets. Earlier he had indicated the reliance on China to help curb Pyongyang "hasn't worked out," and in two successive tweets following the morning missile launch, Trump seemed to poke fun at the North Korean leader, Kim Jong Un. The tweets read:
"North Korea has just launched another missile. Does this guy have anything better to do with his life? Hard to believe that South Korea.....and Japan will put up with this much longer. Perhaps China will put a heavy move on North Korea and end this nonsense once and for all!"
China, for its part, says it has already increased the presence of security agents on its border with North Korea, signed on to U.N. sanctions packages and more strongly enforced sanctions that bar imports of North Korean coal into China. Coal accounts for an estimated 30 percent of North Korea's exports.
The missile flight could represent a significant technological and political accomplishment for North Korea. If Pyongyang has an ICBM, Japan, South Korea and the United States are in a much tougher negotiating position.
Some analysts say it may no longer be realistic to pursue the longstanding U.S. goal of denuclearizing North Korea, and that instead the focus should be on a "freeze" to keep Pyongyang's capabilities from advancing.
Melissa Hanham — a researcher with the James Martin Center for Nonproliferation Studies — says it's time for efforts to engage North Korea at a diplomatic level.
"We need to have really serious conversations amongst ourselves and with allies about what we're willing to trade," she says, "because so far there has been no price that was worth paying to stop their program."
Jihye Lee and Camila Domonoske contributed to this post. Copyright 2017 NPR. To see more, visit http://www.npr.org/.