According to Yonhap, the South Korean media agency, Pyongyang has been unresponsive to Seoul’s communication lines for the second day in a row. 

The South Korean Unification Ministry revealed that the daily cross-border routine call was interrupted yesterday. Pyongyang has also been unresponsive on the military line.

"Regular calls aren't being made due to an unspecified reason from the North's side … We will monitor the situation, including the possibility of a [technical] problem in the North's line," a defense ministry official said, as quoted by the news agency.

It's a customary routine of the two parties to hold bi-daily phone conversations once at 9 a.m. and another at 5 p.m. either through the civil cross-border lines or through military lines. 

In June 2022, the daily phone call routine was interrupted due to technical glitches. In 2020, communication lines were interrupted again due to political tensions caused by leaflets criticizing the North Korean government allegedly distributed by South Korean activists.

Read more: US, S. Korea conduct air drills involving B-52H strategic bomber

Last week, South Korea and the United States held joint air drills involving at least one US nuclear-capable B-52H strategic bomber. 

The DPRK has expressed that it views such exercises as rehearsals for invasion.

Read more: DPRK adopts 'important practical' war deterrence measures: State media

Prior to the drills, the DPRK (North Korea) decided to take "important practical" war deterrence measures. A report by State media indicated that the move was aimed at "coping with the present situation in which the war provocations of the U.S. and South Korea are reaching the red line" but did not elaborate on the measures.