Opposition leader Lee Jae-myung called on the two Koreas to halt a chain of retaliatory actions, such as South Korea's border loudspeaker broadcasts and North Korea's trash balloon campaign, calling it a "childish chicken game" that can lead to war.

On Sunday, South Korea resumed propaganda loudspeaker broadcasts near the inter-Korean border for the first time in six years in retaliation against the North's recent launch of balloons carrying trash into the South.

The broadcasts began after President Yoon Suk Yeol last week endorsed a motion to fully suspend a 2018 inter-Korean tension reduction pact.

"What started as a leaflet can eventually escalate into a localized war or war," Lee said during a Supreme Council meeting. "We must put a stop to this childish chicken game where both North and South Korea become the loser."

The resumption of loudspeaker broadcasts came as Pyongyang sent nearly 1,000 balloons carrying trash to the South since late May in what it called a "tit-for-tat" action against anti-Pyongyang leaflet campaigns by activists in Seoul.

The North had initially said it would temporarily halt the campaign following the South Korean government's warning of "unendurable" measures but launched its third round of trash-filled balloons over the weekend after a North Korean defector group in Seoul sent balloons carrying anti-Pyongyang propaganda leaflets across the border on Thursday. (Yonhap)