North Korea vows to pause trash-balloon campaign after floating 3,500 into South Korea

A North Korean official on Sunday vowed that the secretive country would stop floating trash-carrying balloons over the border into South Korea, but warned that the campaign may resume if South Korean groups continued sending leaflets north.

North Korea sent about 3,500 balloons of various sizes across the border between May 28 and June 2, Kim Kang Il, vice minister of National Defence, said in a statement published by the North's state-run media. Most of the balloons carried garbage, South Korean officials said last week.

Those balloons were described by North Korean officials as a countermeasure after civic groups in Seoul sent leaflets across the border.

The balloon campaign began with about 260 balloons floating across the border in a single day, South Korean officials said. The thousands of balloons sent since then have carried some 15 tons of waste into South Korea, the North Korean official said Sunday.

"We made the ROK clans get enough experience of how much unpleasant they feel and how much effort is needed to remove the scattered wastepaper," Kim said on Sunday, referring to the Republic of Korea, the official name of the South.

He warned that North Korea would continue sending balloons if South Korea resumed its "anti-DPRK leaflet scattering."

"[W]e 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," Kim said.

ABC News' Anthony Trotter, Will Gretsky and Jon Haworth contributed to this report.