North Korea answered the second daily liaison phone call from South Korea on Monday, the unification ministry said, after an earlier call went unanswered and sparked speculation that Pyongyang might be carrying out its threat to abolish a joint liaison office.

Monday's twice-a-day liaison phone calls were a focus of attention as the two sides were to have such calls for the first time since the North vowed to scrap the joint liaison office in anger over anti-Pyongyang propaganda leaflets sent by defectors and activists in the South.

Many had feared that a lack of response would suggest Pyongyang is putting the threat into action. Such fears had appeared to be materializing when the North did not answer the first liaison call from the South on Monday morning, but Pyongyang answered the second call, officials said.

"Calls between the two Koreas at the liaison office in the afternoon proceeded as usual," the unification ministry said in a statement. "North Korea did not mention anything about (its unresponsiveness) in the morning."

Last Thursday, Kim Yo-jong, North Korea leader Kim Jong-un's sister, issued a statement threatening to close the liaison office unless Seoul stops defector groups from sending leaflets into the North.

North Korean defectors and anti-Pyongyang activists have occasionally sent balloons carrying leaflets sharply criticizing the communist regime and its leader, despite repeated calls for a halt to the campaign.

The balloons are often flown with one-dollar bills and USB memory sticks to get more North Koreans to pick up the leaflets.

She denounced the leaflet campaign as a hostile act that violates the peace agreements banning hostilities against each other signed during the summit talks of their leaders in 2018.

She also warned that the North will scrap an inter-Korean military tension-reduction agreement calling for a halt to all hostilities along the border and completely dismantle a now-shuttered joint industrial park in the North's border city of Kaesong.

In a politburo meeting of the Workers' Party that Kim presided over Sunday, however, he did not mention any measures his sister vowed to take in retaliation, including closing down the liaison office.

The inter-Korean liaison office in Kaesong was launched in September 2018 to facilitate cross-border contact and cooperation between the two Koreas following a historic summit agreement between their leaders in April that year.

The two Koreas have made two phone calls daily, at 9 a.m. and 5 p.m., as part of liaison communication.

After the liaison office was closed temporarily over coronavirus concerns earlier this year, liaison officers of the two sides have communicated through telephone and fax lines established between Seoul and Pyongyang.

Despite the silence in liaison communication, the North kept military hotlines running normally, with both sides speaking to each other via a series of hotlines Monday morning, according to the defense ministry. (Yonhap)