North Korean flag (Flicker - dion gillard)A suspected North Korean balloon crossed the inter-Korean border and flew over South Korean airspace Sunday, South Korea’s Joint Chiefs of Staff confirmed Monday.

A South Korean frontline unit in Yeoncheon, Gyeonggi Province first detected the 2-meter balloon, which flew from North Korea, with a terminal observation device, or TOD.

South Korea’s JCS was immediately briefed on the situation. But the JCS ordered the military to reinforce surveillance without taking any countermeasures in light of its assessment that there was nothing significant to report.”

The JCS evaluated that the balloon was used for meteorological purposes, similar to scientific instruments that are used worldwide. The North Korean military has a track record of flying balloons to observe weather conditions including temperature and wind speed.

Meanwhile, South Korea’s Defense Ministry confirmed Monday -- that a suspected Chinese high-altitude surveillance balloon that traversed the US and Canada before being shot down in US airspace on Saturday -- did not fly over South Korea.

The ministry’s denial came after the possible route of the alleged Chinese spy balloon — which US meteorologist Dan Satterfield analyzed based on the model developed by the US government-funded National Oceanic and Atmospheric Administration — raised the possibility that the balloon may have crossed over the southern part of the Korean Peninsula.

“We’ve assessed that the Chinese balloon did not pass through our airspace in light of its traveling altitude and our air surveillance capabilities,” Defense Ministry spokesperson Jeon Ha-kyu told a regular press briefing. “Our air-defense and air traffic control radars cover the entire country’s airspace, but there was none related trajectory detected by our military’s radar at that period.”