The presidential National Security Council (NSC) strongly condemned North Korea's launch of two short-range ballistic missiles into the East Sea on Sunday, saying it was a violation of UN Security Council resolutions.

President Yoon Suk-yeol was briefed immediately after the launch and the NSC held a meeting presided over by National Security Adviser Kim Sung-han, according to the presidential office.

Sunday's launch was the North's seventh missile test in under two weeks.

The council "strongly condemned" a flurry of ballistic missile tests by North Korea as a "clear violation of the UN Security Council and an act that increases tension on the Korean Peninsula and in the region," the presidential office said in a statement.

South Korea's military will further bolster its joint defense posture through joint drills with the United States and security cooperation among Seoul, Washington and Japan, while preparing thoroughly against additional provocations by the North, it said.

North Korea fired the two short-range ballistic missiles toward the East Sea earlier in the day, after Seoul and Washington wrapped up a naval exercise, involving a US aircraft carrier, the previous day.

Military officials said they detected the launches from the Munchon area in Gangwon Province between 1:48 a.m. and 1:58 a.m., and that the missiles flew some 350 kilometers at apogees of around 90 km at top speeds of Mach 5. (Yonhap)