North Korean broadcasts reportedly involve music praising top leader Kim Jong Un and its regime, and messages denouncing South Korean President Park Geun-hye.
Such warnings came a day after a U.S. B-52 bomber, capable of delivering nuclear missile, flew over South Korea's airspace in response to what the DPRK claimed was its first successful test of a hydrogen bomb last Wednesday.
North Korea has been roundly condemned for its nuclear tests, including this one.
North Korea state television KCNA broadcast a photo of the North Korean leader with hundreds of scientists, workers and officials who participated in the latest test. KCNA said Kim congratulated the group for "succeeding in the first H-bomb test... and bringing about a great, historic event".
"This was a demonstration of the ironclad U.S. commitment to our allies in South Korea, in Japan, and to the defense of the American homeland", said Adm. Harry B. Harris Jr., commander of U.S. Pacific Command in Hawaii.
"The North initially operated its own loudspeakers at two locations and has now expanded to several locations", a South Korean government source was quoted as saying by local news agency Yonhap.
If we are not awakened by North Korea's latest test, what will it take?
US B-52 strategic bomber flying over South Korea in a show of force following North Korea's nuclear test, South Korea, 10 January 2016. Seoul on Monday continued anti-Pyongyang propaganda broadcasts across the border and announced that it would further limit the entry of South Koreans to a jointly run factory park in North Korea.
Pyongyang on Wednesday carried out its fourth nuclear test, angering the worldwide community and raising tensions with neighbouring South Korea.
South Korea and the USA are also in discussions to potentially deploy additional strategic assets to the Korean peninsula, the South Korean Defense Ministry said.
The North also initiated propaganda broadcasts on Monday from loudspeakers situated on its border with the South, in a tit-for-tat response to the South's decision on Friday to resume such broadcasts.
Scaparrotti was touring the base, which is 55 kilometers south of the capital Seoul, together with South Korean Joint Chiefs of Staff Chairman General Lee Sun-jin.
An analysis by the U.S. Geological Survey fixed the coordinates of the bomb test in northeastern North Korea, an isolated and heavily forested area about 6,000 feet in elevation.
Officials there say the test has triggered an outpouring of national pride.
South Korea is hosting the talks in hopes of persuading a less forthcoming China, a permanent member of the Security Council and North Korea's closest economic partner, to take a stronger stand against Pyongyang's provocations, South Korean newspaper Seoul Economy Daily reported.