North Korea test fired several short-range projectiles Saturday morning from the country's eastern coast, according to South Korean officials.
The projectiles flew 70 to 200 kilometers (43 to 125 miles) before crashing into the sea, officials said, adding that both South Korean and US authorities were analyzing the details to glean further insights. The launch took place around at 9:06 a.m. (8:06 p.m. ET Friday).
If confirmed, the test is understood to be the first missile launch from North Korea since late 2017 -- and the first since US President Donald Trump began meeting the country's leader Kim Jong Un.
The move could escalate tensions with the United States, coming two months after Trump walked away from a second summit between the two leaders.
"At present, our military has intensified surveillance and vigilance to prepare for North Korea's additional launches," South Korea's Joint Chiefs of Staff said in a statement, adding that Seoul and Washington were "working closely together and maintaining their full preparedness."
An earlier statement from South Korea's Defense Ministry said a "missile" had been fired.
A US official with knowledge of the initial assessment says there were multiple firings to the east by North Korea. Intelligence analysts are still sifting data to determine if projectiles, missiles or both were fired. Earlier, South Korea said that the term projectiles could include ballistic missiles, rockets or use of a multi rocket launcher.
In a statement, White House Press Secretary Sarah Sanders said: "We are aware of North Korea's actions tonight. We will continue to monitor as necessary."
Japan's Defense Ministry said there was no evidence the projectiles had landed in its territorial waters.
Saturday's launch comes a few weeks after North Korea said it conducted a tactical guided weapons firing test, according to state media. In a report from the Korean Central News Agency (KCNA), Kim praised that test as a "great historic event in strengthening the combat capability of the People's Army."
Following the launch, South Korea's Foreign Minister Kang Kyung-wha spoke with her US counterpart, Secretary of State Mike Pompeo, about the situation.
"The two sides agreed to continue the further analysis of today's launch and continue to communicate while carefully handling (the situation)," South Korea's Foreign Ministry told reporters via text message.
North Korea's missile program made major strides in 2017, when Pyongyang claimed it had successfully test fired three intercontinental ballistic missiles. Experts said the Hwasong-15, which was launched in late November 2017, likely had the capability to hit much of the United States.
Rising international tension over Pyongyang's weapons program eased dramatically in 2018 when Kim indicated his willingness to negotiate, and later met with South Korea's President Moon Jae-in and US President Donald Trump.
After making some progress in 2018, talks appeared to stall this year when Kim and Trump's second meeting in Hanoi, Vietnam abruptly ended with no agreement.
"Sometimes you have to walk," Trump said during a news conference after the talks, which broke up earlier than planned. North Korean state media later acknowledged that the meeting hadn't gone as well as expected.
Pyongyang has been pushing for more sanctions relief in exchange for denuclearization, while the US has demanded greater evidence that the country is prepared to reduce its nuclear arsenal.
Analysts said the projectiles fired on Saturday were unlikely to fall within the category of weapons that Pyongyang had promised Washington to stop testing after negotiations began last year.
"With North Korea never promising to completely stop all missile testing -- it only promised a self-imposed moratorium of testing long-range missiles such as ICBMs that can hit the US homeland -- we should not be shocked by North Korea's short-range launch," said Harry J. Kazianis, Korean studies director at the Washington-based Center for the National Interest.
"Clearly, Pyongyang is frustrated with the conclusion of the recent summit with Washington in Vietnam that did not produce any breakthrough. It also seems clear that North Korea is angry over what appears to be a lack of flexibility in the Trump Administration's position on relieving sanctions, sticking to a policy of 'maximum pressure'."
Kazianis added that it appeared Kim "has decided to remind the world -- and specifically the United States -- that his weapons capabilities are growing by the day. My fear is that we are at the beginning stages of a slide back to the days of nuclear war threats and personal insults, a dangerous cycle of spiking tensions that must be avoided at all costs."
Last month, Kim and Russian President Vladimir Putin met for the first time in Russia. Analysts say the meeting may have been an attempt by Putin to reinsert Moscow into the discussion over one of the region's most pressing problems. So far, talks have primarily involved the US and South Korea.