North Korea is believed to have launched two short-range ballistic missiles into the East Sea on Monday, in its fourth show of force this year.
South Korea's Joint Chiefs of Staff said the projectiles were fired eastward from Sunan airport in Pyongyang.
The JCS said authorities are further analyzing the tests while the military is maintaining a heightened readiness posture in the case of further provocations.
Japan's Prime Minister's Office also said it detected a possible ballistic missile launch from North Korea.
As talks with the United States remain stalled, North Korean has been pushing forward with its weapons development.
Earlier this month, the Kim Jong-un regime tested two hypersonic missiles in violation of United Nations Security Council resolutions, and on Friday launched train-borne missiles in response to new U.S. sanctions.
