North Korea launched what appeared to be a ballistic missile into the sea to the east of the Korean Peninsula on Sunday, Japan's defense ministry said.
South Korea's defense ministry said the rival North had fired an unidentified projectile. Japanese public broadcaster NHK said it had come down outside Japan's exclusive economic zone.
Only hours later, North Korea fired a second missile off its east coast, local Yonhap News outlet reported.
A day earlier, North Korea dismissed a resolution by the UN nuclear watchdog against Pyongyang's nuclear program, in a statement through state media.
North Korea condemns US-Japan-South Korea naval drill
Pyongyang last week also condemned a US-led naval drill including South Korea and Japan, which ran from August 29 to September 10 near Guam.
North Korea's Kim Yo Jong, the influential sister of leader Kim Jong Un, on Friday blamed US-led military drills for "ever-worsening" tensions on the Korean Peninsula and vowed no change in the country's course to strengthen its nuclear arsenal.
South Korea’s presidential office convened a National Security Council (NSC) meeting on Sunday following the reports of North Korea's launch of short-range ballistic missiles into the East Sea from the Wonsan area.
Condemning the launch, the second in about a week following a previous test on September 12, the NSC urged Pyongyang to immediately cease missile activity, warning that the test directly violates United Nations Security Council resolutions.