Pyongyang test-fired two mid-range missiles at 2:35 a.m. and 2:42 a.m. local time into the sea off its east coast.
South Korean Defense Ministry spokesman Kim Min-seok convened an emergency briefing Wednesday, at which he announced, "North Korea's ballistic missile launch clearly violates U.N. Security Resolutions and is a grave provocation to Republic of Korea (South) and the international community."
South Korea's foreign ministry warned Pyongyang against further provocations: "The government calls on the North to immediately halt such provocations and fully comply with its obligations and promises with the international community."
The missiles' trajectory suggests they were part of the Rodong class, as they exceeded altitudes of 160 km and a speed of Mach 7.0, according to Kim. The last time North Korea fired a Rodong-class missile was in 2009.
The latest ballistic missiles were launched as leaders from South Korea, Japan, and the United States met Tuesday at the Nuclear Security Summit at The Hague, where they focused on the security threat North Korea poses.
U.S. President Barack Obama said just prior to the meeting, "Over the last five year, close coordination between our three countries has succeeded in changing the game with North Korea, and our trilateral cooperation has sent a strong signal to Pyongyang that its provocations and threats will be met with a unified response and that the U.S. commitment to the security of both Japan and the Republic of Korea is unwavering, and that a nuclear North Korea is unacceptable."