South Korea's military on Tuesday said it would resume all military activities along the demarcation line separating the two Koreas and in northwestern islands after suspending an inter-Korean military agreement.

The suspension of the military agreement with the North, which President Yoon Suk-yeol approved earlier Tuesday, is in response to North Korea's decision to send hundreds of balloons carrying trash over the border.

"The South Korean military makes it clear that it will take all necessary measures to protect the lives and safety of its people in response to North Korea's provocations," a Defense Ministry official said in an emergency briefing.