North Korea has said that it will stop sending balloons carrying garbage across the border with South Korea, but vowed to restart the practice if activists from the South resume flying anti-regime leaflets.

North Korean Vice Minister of Defense Kim Kang Il said in a statement carried by state-run media that Pyongyang had sent more than 3,500 balloons carrying 15 tons of waste over the border from Tuesday through Sunday.

Kim said late Sunday that the “unpleasant” measures had given the South Korean side a taste of “how much effort is needed” to clean up the waste, saying that Pyongyang would be “temporarily” halting its actions.

“But, if the ROK clans resume anti-DPRK leaflet scattering, we will correspond to it by intensively scattering wastepaper and rubbish hundred times the amount of scattered leaflets and the number of cases, as we have already warned,” he said in the statement carried by the North’s official Korean Central News Agency.

ROK and DRPK are the abbreviations for the official names of the South and North, the Republic of Korea and the Democratic People's Republic of Korea, respectively.

North Korean defectors and activists in the South have long used balloons to fly money, medicine, leaflets and thumb drives filled with Korean dramas and information on the more prosperous South across the border — a practice that at least one group hinted was likely to continue.

The head of Fighters for a Free North Korea, a defectors' group, told local media in South Korea that its basic stance would not change, and that the group would continue to send balloons when winds blow in a northern direction.

"But we can consider temporarily stopping if Kim Jong Un politely apologizes for letting South Koreans be hit with trash," Park Sang-hak was quoted as saying in reference to the North Korean leader.

A cigarette butt found in one of the balloons believed to have been sent by North Korea to the South is seen in Seoul in this picture released Sunday.
A cigarette butt found in one of the balloons believed to have been sent by North Korea to the South is seen in Seoul in this picture released Sunday. | South Korean Defense Ministry / via REUTERS

Nearly 1,000 of the North Korean balloons had been sent since Tuesday, according to South Korean authorities.

Initial reports said that some of the North Korean balloons recovered had been carrying feces, a claim the South Korean military dismissed — though it did note that some of the garbage appeared to be compost.

South Korea’s top security official on Sunday vowed “unendurable" measures in response, calling the North’s actions “despicable provocations that could not have been imagined by a normal country.”

"As we warned Friday, we will take measures that will be unendurable for North Korea," the Yonhap news agency quoted national security adviser Chang Ho-jin as saying. "We will not sit idly by against any additional provocation by North Korea."

Chang stressed that, if North Korea repeats its act, Seoul’s “response will only become more powerful."

These steps could include the resumption of propaganda campaigns via loudspeakers along the border, Yonhap quoted an unidentified high-ranking South Korean Presidential Office official as saying.

"We will not rule out the possibility of restarting our loudspeaker campaign," the official said, adding that some concrete action will be taken "in the very near future."

The loudspeaker campaign — a source of inter-Korean tensions that blared K-pop music and criticism of leader Kim Jong Un across the heavily armed border — was halted amid a thaw in relations in 2018 under then-President Moon Jae-in.

North Korean defector Thae Yong-ho, who now serves as a South Korean lawmaker with President Yoon Suk-yeol’s People Power Party, has said that what Kim Jong Un “fears the most” are loudspeaker broadcasts targeting North Korean soldiers deployed along the border.

Though the two Koreas have remained technically at war since the Korean War ended in just an armistice in 1953, Kim has this year labeled the South his nation’s “principal enemy” while abolishing agencies focused on reunification and threatening to enshrine in the North’s constitution a goal of “completely occupying, subjugating and reclaiming” its southern neighbor.

In contrast with North Korea's latest low-tech propaganda push, the nuclear-armed country has poured resources into its nuclear and missile programs, threatening Seoul with a spate of weapons tests, military exercises — and even a failed launch of a spy satellite — this year alone.