The South has long broadcast a mix of news, music and propaganda messages urging the North's soldiers to defect through huge speakers along the heavily-fortified border, with operations varying depending on the swings of volatile inter-Korea ties.

The North plays propaganda of its own.

Relations have improved markedly in recent months, with the North announcing at the weekend that it would not conduct any more nuclear tests or long-range missile launches.

The latest developments come ahead of a summit between the North's leader Kim Jong Un and the South's President Moon Jae-in on Friday, and with Kim expected to meet US President Donald Trump later.

"We stopped loudspeaker broadcasts... as of today in order to ease military tension and to create a peaceful climate... ahead of the 2018 inter-Korea summit," Seoul's defence ministry said in a statement.

The two neighbours remain technically at war after the 1950-53 Korean War ended with an armistice instead of a peace treaty, with tens of thousands of soldiers guarding the mine-infested land border.

Friday's meeting, to be held on the southern side of the border truce village of Panmunjom, is only the third summit ever between the two Koreas after encounters in Pyongyang in 2000 and 2007.

All eyes are on whether Kim will promise any concrete steps towards dismantling the North's nuclear arsenal.

The young leader, believed to be in his mid-30s, has overseen four of the country's six nuclear tests and Pyongyang hails its weapons as a "treasured sword" protecting the country from potential US invasion.

Kim has also overseen dozens of missile tests, including intercontinental ballistic missiles (ICBMs) capable of reaching the US mainland.