North and South Korea have ended the propaganda broadcasts they have blasted across their common border since the end of the Korean war in 1953.
There are around 100 South Korean posters along the border
Equipment like loudspeakers and billboards will be dismantled as part of an agreement to reduce tensions on the heavily fortified frontier.
But the North has remained defiant to demands it scrap its nuclear ambitions.
It said six-nation talks due to open on 23 June were unlikely to make progress unless the US shifted position.
A North Korean Foreign Ministry said "nothing will be expected from the forthcoming talks" if the US continued to insist it completely dismantled its nuclear programmes, adding that such a demand could only "be forced on a defeated country".
The propaganda broadcasts have been a symbol of the divide between the two Koreas since the Cold War.
Giant North Korean speakers broadcast martial music and praises to the country's rulers.
The South responded with popular music and lectures on freedom and democracy.
But just before midnight on Monday - the fourth
anniversary of an historic inter-Korean summit - the speakers fell silent.
"We announce the historic fact that our voice of freedom broadcasts are being brought to closure," the last South Korean broadcast said.
The decision to end the broadcasts came as part of an unprecedented agreement between the two countries' militaries aimed at easing tensions.
Heavily fortified border has separated the two Koreas since 1950-53 war
240 km long and 4 km wide, the DMZ takes up about 5% of the Korean peninsula
Both sides have broadcast propaganda over the border since truce was signed
In the coming weeks and months, propaganda speakers along the border will be dismantled, along with electronic signboards designed to flash messages.
Seoul currently has around 100 posters along the land border, while Pyongyang has 200.
A group of about 100 North Koreans is in Seoul to mark the anniversary of the inter-Korean summit, which at the time was heralded as an important step forward in inter-Korean relations.
But little progress has been made since - especially over North Korea's alleged nuclear weapons programme.
There will now be another chance for negotiations on the issue later this month.
China announced on Tuesday that it would host the third round of six-nation talks on North Korea's nuclear weapons ambitions from 23 to 26 June, in Beijing.
North Korea has said it was willing to freeze its nuclear programme in return for economic aid, and would only dismantle it if given assurances the US would not invade.
Correspondents say the North appears to be trying to improve ties with its neighbours, like South Korea and Japan, while waiting to see the outcome of the US election before it decides its next moves with Washington.
South Korean President Roh Moo-hyun has offered numerous incentives to the North to scrap its nuclear weapons programme.
In a speech to mark the anniversary of the inter-Korean summit, he said the South would help to rebuild the North's infrastructure and enhance industrial production, as well as assist to join international organisations.
"Inter-Korean co-operation will be accelerated if the nuclear issue is resolved, and we are preparing comprehensive and concrete plans for that," he said.