North Korea fired two short-range missiles Saturday in the direction of the Sea of Japan, also known as the East Sea, according to an assessment cited by two US officials.
North Korea has been launching short-range ballistic missiles regularly in recent weeks. Saturday's launches were about 15 minutes apart.
One week ago, the country fired two short-range ballistic missiles into the waters off its east coast, just minutes before Pyongyang vowed to cut off dialogue with Seoul and referred to South Korean President Moon Jae-in as an "impudent guy."
South Korea's presidential Blue House said a National Security Council meeting will be convened.
"Regarding North Korea's launch of projectiles and the National Security Council meeting led by the chief Chung Eui-yong will be held from 7:30p ET (8:30 a.m. Local time)," a Blue House official said.
Japan's Coast Guard and Defense Ministry also acknowledged the apparent ballistic missile launches on their websites.
The Coast Guard said: "It seems that a ballistic missile was fired from North Korea. Vessels should pay attention to future information, and if any fallen objects are recognized, please report the relevant information to the Japan Coast Guard without approaching them."
Japan's Defense Ministry said the missile was unlikely to land in Japan's territory or exclusive economic zone.
Experts believe Pyongyang has been test-firing much more technologically advanced weaponry than seen in previous years, including solid-fuel missiles that are easy to deploy on short notice and one the North Koreans may have been able to maneuver in flight.
US President Donald Trump has downplayed the weapons tests, but analysts say they should give reason for Washington to worry. Trump will head to the G7 summit in France this weekend.
In 2017, North Korea made a similar provocation, firing missiles on May 13 and 21, just before the G7 began in Italy.
This is ninth round of launches since May after a long break of tests since 2017. This happens amid heightened tensions after South Korea notified Japan it was ending a military intelligence information-sharing agreement because of a trade dispute.
Short-range missile tests are a violation of UN resolutions.
This is a developing story. Check back for updates.