North Korea will restore cross-border communications with its southern counterpart from Monday after dropping them in August, the official KCNA news agency reported.
The decision comes just days after Pyongyang sparked international concern with a series of missile tests in the span of a few weeks. The tests prompted the UN Security Council to hold an emergency meeting.
The two Koreas had signalled a surprise thaw in relations in late July by announcing the restoration of cross-border communications, which were severed more than a year earlier.
But the detente was short-lived, as North Korea stopped answering calls just two weeks later.
North Korean leader Kim Jong Un "expressed the intention of restoring the cut-off north-south communication lines," KCNA said early Monday, reporting the move was an attempt to establish "lasting peace" on the Korean peninsula.
"The relevant organs decided to restore all the north-south communication lines from 9:00 on Oct. 4," KCNA added.
Pyongyang had unilaterally cut off all official military and political communication links in June last year over activists sending anti-Pyongyang leaflets across the border.
The two sides said on July 27 this year that all lines were restored.
Their joint announcement, which coincided with the anniversary of the end of the Korean War, was the first positive development since a series of summits between Kim and the South's President Moon Jae-in in 2018 failed to achieve any significant breakthrough.
Officials from the two sides held a first phone call that same morning, Seoul's unification ministry said, with the defence ministry adding that military hotlines were also back to normal operation.
The two sides also revealed at the time that Kim and Moon had exchanged a series of letters since April in which they agreed that re-establishing hotlines would be a productive first step in rebooting relations between the two rivals who, despite the end of their 1950-53 conflict, remain technically at war.
But the cross-border communication lasted for just two weeks. The North began ignoring calls in August, taking issue with joint US-South Korean military drills.
In the period since, the North — which had until recently been biding its time since the change in US administrations in January — held a series of tension-raising missile tests.
In September, it launched what it said was a long-range cruise missile, and earlier this week it tested what it described as a hypersonic gliding vehicle, which South Korea's military said appeared to be in the early stages of development.
On Friday it said it had successfully fired a new anti-aircraft missile.
Pyongyang slammed the UN Security Council Sunday for holding an emergency meeting over the missile tests, accusing member states of toying with a "time-bomb."