South Korea said Wednesday it had dismantled a Christmas tree-shaped tower near the border with North Korea which had previously been used for a seasonal lights show that drew angry protests from the atheist regime in Pyongyang.

North Korea has repeatedly demanded the destruction of the 60-foot (20-meter) high steel tower on top of a military-controlled hill just three kilometers from the heavily-fortified border.

North Korea has freed one of three Americans detained in the isolated country, and in a surprise move allowed a Pentagon plane to land in Pyongyang on Tuesday to fly him home.

Jeffrey Fowle, who was arrested earlier this year and is in apparent good health, "has been allowed to depart the DPRK," White House spokesman Josh Earnest said, adding the 56-year-old was already on his way home.

South Korea's unification minister on Tuesday urged activists planning to float anti-Pyongyang leaflets into North Korea to act prudently, ahead of proposed high-level talks.

The appeal comes as military tensions run high between the two Koreas following a series of minor border skirmishes that have raised military tensions.

North Korea warned Monday of an "unpredictable" retaliatory strike against South Korea following a series of minor border skirmishes that have raised military tensions ahead of planned high-level talks.

Troops from the two sides exchanged small arms fire on Sunday after South Korean troops fired warning shots at a North Korean patrol moving towards the military demarcation line that marks the border on the peninsula.

North Korea warned Monday of an "unpredictable" retaliatory strike against South Korea following a series of minor border skirmishes that have raised military tensions ahead of planned high-level talks.

Troops from the two sides exchanged small arms fire on Sunday after South Korean troops fired warning shots at a North Korean patrol moving towards the military demarcation line that marks the border on the peninsula.

North and South Korean troops briefly exchanged fire Sunday in the latest in a series of minor border skirmishes that have raised military tensions on the divided peninsula.

The South's defense ministry said the exchange inside the Demilitarized Zone (DMZ) that separates the two rivals lasted only 10 minutes.

North Korea's state media on Friday reported another public appearance by leader Kim Jong-Un, his second in four days after an extended absence that has seen him re-emerge with a walking stick.

The North's ruling party newspaper Rodong Sinmun ran front page pictures of a smiling Kim, a black cane in his left hand, inspecting two high rise apartment complexes built to house faculty members of a university specialising in nuclear research.

North Korea has accused the South of deliberately undermining efforts to reduce military tensions and warned that prospects for the resumption of a high-level dialogue between the two rivals are "gloomy".

In a lengthy, 1,500-word dispatch late Thursday, that condemned the South for its "persecution mania", hypocrisy and arrogance, the North's official KCNA news agency offered its version of secretive military talks on Wednesday that ended in stalemate.

North and South Korea held their first high-level military talks for seven years on Wednesday, the South's Yonhap news agency reported, following a series of recent incidents on their land and maritime borders.

Yonhap said the talks between generals on both sides was held at the border truce village of Panmunjom.

North Korean leader Kim Jong-Un has finally resurfaced with the help of a walking stick after a prolonged, unexplained absence that fueled rampant speculation about his health and even rumors of a coup in the nuclear-armed state.

State media on Tuesday reported that Kim, who had not been seen in public for nearly six weeks, made an inspection tour of a newly-built housing complex in Pyongyang and a science institute.