An intense rapprochement saw the two rivals march together at the South's Pyeongchang Winter Olympics last month, with the North's leader Kim Jong Un sending his sister as a special envoy to the event.

Kim Yo Jong's trip was the first visit to the South by a member of the North's ruling dynasty since the end of the Korean war and her appearance at the Games' opening ceremony made global headlines.

South Korean President Moon Jae-in has sought to use the Pyeongchang Games to open dialogue between Washington and Pyongyang in the hopes of easing a nuclear standoff that has heightened fears over global security.

He chose five senior officials -- including national security advisor Chung Eui-yong and spy chief Suh Hoon -- to visit Pyongyang on Monday.

Suh is a veteran in dealings with the North. He is known to have been deeply involved in negotiations to arrange two previous inter-Korean summits in 2000 and 2007.

The 10-member group -- five top delegates and five supporting officials -- will fly to Pyongyang on Monday afternoon and return to Seoul on Tuesday.

The North's official Korean Central News Agency also announced their impending visit in a one-paragraph dispatch.

Other members include Suh's deputy at the National Intelligence Service as well as Chun Hae-sung, the vice minister of Seoul's unification ministry, which handles cross-border affairs.

The delegation will fly to the US on Wednesday to explain the result of the two-day trip to officials in Washington, according to the South's presidential office.

Last year, in defiance of UN sanctions, the isolated and impoverished North staged its most powerful nuclear test and test-fired several missiles. Pyongyang claims it can now hit the US mainland.

The North's leader Kim and US President Donald Trump traded threats of war and personal insults, sending tensions soaring before a thaw in the run-up to the Winter Olympics.

Moon, who advocates dialogue with the North's nuclear-armed regime, said last week that Washington needs to "lower the threshold for talks" with Pyongyang.

But the US has ruled out any possibility of talks before the North takes steps towards denuclearisation, and imposed what Trump hailed as the "toughest ever" sanctions on Kim's regime late last month.