North Korea fired a suspected long-range ballistic missile toward the East Sea on Wednesday, amid tensions caused by Pyongyang's accusations against US spy aircraft operations earlier this week, the South Korean military said.
South Korea's Joint Chiefs of Staff (JCS) said it detected the launch from an area in or around Pyongyang at about 10 a.m. (local time) without elaborating further, reports Yonhap News Agency.
"While strengthening our monitoring and vigilance, our military is maintaining a full readiness posture in close cooperation with the United States," the JCS said.
The North's last long-range missile launch took place on April 13, when it fired a Hwasong-18 solid-fuel intercontinental ballistic missile.
On Monday and Tuesday, Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un, issued sharp-tongued statements claiming that US military spy aircraft "intruded" into the area over the North's exclusive economic zone (EEZ).
Kim Yo-jong warned that the North will take "clear and resolute" actions against US surveillance flights within the North's "economic water zone," claiming a "shocking" incident could occur.
The South Korean military has dismissed her remarks, saying freedom of navigation and overflight are ensured in the EEZ.
The latest launch came as major diplomatic and security gatherings are taking place this week, including the ongoing NATO Summit in Lithuania and the ASEAN Regional Forum in Indonesia.
At the NATO Summit, South Korean President Yoon Suk Yeol is expected to discuss security cooperation against North Korea's military threats with other leaders.
The North's saber-rattling also came after its failed launch of a space rocket carrying its first military reconnaissance satellite in late May.
The rocket crashed into the Yellow Sea after an abnormal starting of the second-stage engine, according to the North's state media.