SEOUL, June 23 (CGTN) - According to military officials from the Republic of Korea (ROK), their neighbor Pyongyang is reinstalling propaganda loudspeakers along the border area – along with millions of leaflets, already confirmed by Pyongyang, in preparation for "retaliatory punishment."

The Democratic People's Republic of Korea (DPRK) has been detected setting up loudspeakers again "in multiple places" inside the Demilitarized Zone (DMZ) from around Sunday, after removing them under a 2018 summit agreement with ROK. Earlier, it had dismantled dozens of loudspeakers in around 40 areas near the tense the DMZ following up their commitment on the Panmunjom Declaration.

"Such moves were spotted in more than 10 regions, which have taken place simultaneously," said an official of ROK's Joint Chiefs of Staff to Yonhap.

"We are closely monitoring the North's (DPRK's) moves to wage psychological warfare. We maintain a tight readiness posture to properly respond to any eventualities," he added.

Earlier on Monday, Pyongyang also confirmed preparation of thousands of balloons and millions of leaflets, a day after the country said it was preparing to begin an anti-ROK leaflet campaign following a series of condemnations of Seoul after anti-DPRK leaflets floated over the border.

Defectors in the ROK send such leaflets, with content criticizing the DPRK. The messages are usually attached to balloons or floated in bottles.

"The preparations for the largest-ever distribution of leaflets against the enemy are almost complete," a report by the Korean Central News Agency (KCNA) said.

"Publishing and printing institutions at all levels in the capital city have turned out 12 million leaflets of all kinds reflective of the wrath and hatred of the people from all walks of life," it said.

More than "3,000 balloons of various types capable of scattering leaflets deep inside South Korea (ROK), have been prepared," KCNA added.

Inter-Korean relations have been frozen for months, following the collapse of a summit in Hanoi between DPRK leader Kim Jong Un and U.S. President Donald Trump early last year.

That meeting foundered on what the DPRK would be willing to give up in exchange for lifting sanctions on the country.