By Hyunsu Yim
SEOUL (Reuters) - North Korea said on Sunday it would stop sending balloons carrying trash over the border to South Korea but vowed to resume the practice if anti-North Korean leaflets are flown over again from the South.
South Korea has had enough experience of how unpleasant it is and how much effort it takes to collect trash after North Korea sent 15 tons of it using 3,500 balloons, the North's vice-minister of defence Kim Kang Il said in a statement carried by state media outlet KCNA.
South Korea said it would take "unendurable" measures against North Korea for sending the trash balloons over the border, which could include blaring propaganda from loudspeakers directed at the North.
The announcement from President Yoon Suk Yeol's office followed a meeting of his National Security Council on a response to what Seoul said were more than 700 balloons carrying trash that Pyongyang sent over the heavily fortified border to annoy its neighbour.
The council condemned the balloons, and simultaneous GPS jamming, as an "irrational act of provocation".
Seoul did not rule out resuming the loudspeaker blasts, which it stopped in 2018 after a summit with North Korean leader Kim Jong Un, a senior official at Yoon's office told reporters.
The democratic South and the communist North remain technically at war since the 1950-1953 Korean War ended in an armistice rather than a peace treaty. Seoul is a firm U.S. ally whose sophisticated military regularly holds drills with the U.S., while Pyongyang is developing missile and nuclear technology that Seoul and Washington say violates U.N. resolutions.
North Korea has said its balloons were in retaliation for a propaganda campaign by North Korean defectors and activists in South Korea, who regularly send inflatables containing anti-Pyongyang leaflets, food, medicine, money and USB sticks loaded with K-pop music videos and dramas across the border.
The North Korean balloons carrying garbage such as cigarette butts, cloth, paper waste and plastic were found across the capital Seoul from 8 p.m. on Saturday to 1 p.m. on Sunday (1100 GMT on Saturday to 0400 GMT on Sunday), South Korea's Joint Chiefs of Staff said.
They said the military was monitoring the starting point and conducting aerial reconnaissance to track down and collect the balloons, which have large bags of trash suspended beneath them.
South Korean officers with rifles were picking up and bagging what appeared to be trash from the balloons in cordoned-off areas, local media footage showed.
North Korea on Wednesday sent hundreds of balloons carrying trash and what was labelled as manure across the border as what it called "gifts of sincerity". Seoul responded angrily, calling the move base and dangerous.
North Korea has not commented on the weekend balloons.
South Korean Defence Minister Shin Won-sik told U.S. Defense Secretary Austin Lloyd at a conference in Singapore on Sunday that the balloons violated the armistice agreement, according to South Korea's military.
The two reaffirmed a coordinated response to any North Korean threats and provocations based on the South Korea-U.S. alliance's combined defence posture, it said.
Emergency alerts were issued in North Gyeongsang and Gangwon provinces and some parts of Seoul on Sunday, urging people not to touch the balloons and to alert police.