Seoul, Apr 10 (IANS): North Korea remained unresponsive to daily routine calls with South Korea through an inter-Korean liaison communication channel and a military hotline for a fourth straight day on Monday, according to the Seoul's government.

South Korea's Unification Ministry said the North appears to have "unilaterally" cut off the liaison communication line, as the country has not answered routine calls since April 7, reports Yonhap News Agency.

The two Koreas are supposed to hold phone calls twice a day, at 9 a.m. and 5 p.m., via their joint liaison channel.

Calls from the liaison hotline do not take place on weekends.

Calls through a military hotline also went unanswered for the fourth straight day on Monday, according to the South's Defence Ministry.

The Unification Ministry said it puts more weight on the North's "unilateral" move to block the liaison communication channel.

"While monitoring the situation, the government is reviewing how to respond (to the North's move). It will not take long for us to issue an official stance," Koo Byoung-sam, the ministry's spokesperson, told a regular press briefing.

It is unclear why the North remains unresponsive to such daily calls with the South.

Daily phone calls via inter-Korean communication channels went unanswered in the past due to technical reasons.

Last June, Pyongyang did not respond to a regular hotline call apparently due to technical glitches caused by heavy rains.

In July 2021, the North restored the inter-Korean hotline, about a year after it severed the contact channel in protest of Seoul activists' leaflet campaigns critical of Pyongyang.

The country again did not answer calls via the liaison line in August that year for about two months apparently due to its protest against Seoul-Washington's military exercises.