South Korea's President Yoon Suk Yeol fully suspended on Tuesday a 2018 tension-reducing military deal with the North in response to a bombardment of trash-carrying balloons sent by Pyongyang last week.

The agreement, signed during a period of warmer ties, was already largely void as Seoul had partially suspended it last year in response to North Korea putting a spy satellite into orbit, prompting Pyongyang to say it would not honour it at all.

But Seoul's security officials said that respecting even some portions of the deal was hindering their ability to defend against the North's provocations, which include floating nearly 1,000 balloons carrying garbage such as cigarette butts and manure across the border last week.

President Yoon "has just approved the 'September 19 (2018) Military Agreement Suspension Proposal'," which the cabinet had already signed off on, his office said in a statement.

Yoon's approval means the agreement is suspended with immediate effect.

The move will allow the South to resume live fire drills and re-start loudspeaker propaganda campaigns along the border with the North.

The South has used the loudspeaker campaigns -- considered a psychological warfare tactic dating back to the 1950-53 Korean War -- as a countermeasure to what it deems serious North Korean provocations.

For example, it last deployed them from 2016, after Pyongyang conducted its fourth nuclear test, until calling them off days before the historic 2018 inter-Korean summit where the tension-reducing military deal was signed.

The loudspeaker campaigns involve South Korea using large megaphones to broadcast everything from K-pop to anti-regime propaganda into areas close to the demilitarised zone separating the two countries, which remain technically at war.

The broadcasts infuriate Pyongyang, which has previously threatened artillery strikes against the loudspeaker units unless they were switched off.

Pyongyang said the trash balloons were retaliation for similar missives sent northwards by South Korean activists.

An anti-Pyongyang group in the South revealed on Monday that they had sent around 2,000 USB flash drives containing songs by South Korea's mega trot singer Lim Young-woong, as well as other K-pop music and K-drama series, via balloons into the North on May 10.

The hermit country is extremely sensitive about its people gaining access to South Korea's flourishing popular culture.

According to a report by the United Nations, Pyongyang enacted a law in 2020 which has enabled them to punish anyone possessing or distributing a large amount of media content from the South by life imprisonment or even the death penalty.

Seoul has also said Pyongyang attempted to jam GPS signals for several days last week.

The North called off the balloon bombardment Sunday, saying it had been an effective countermeasure -- but warning that more could come if needed.