Takeoffs and landings at Incheon International Airport were temporarily suspended on Monday morning due to trash-laden balloons sent from North Korea.

South Korea's Joint Chiefs of Staff said Seoul may respond militarily to any casualties caused by North Korea's launching of so-called "trash balloons."

South Korea warned of possible military actions if North Korea continues to fly more trash balloons across the border, a rare direct threat of retaliation since Pyongyang started sending them in May.

South Korea said Monday it would take "decisive military action" if anyone is killed by the wave of trash-carrying balloons being launched across the border by North Korea.