South and North Korea had a daily phone call via the liaison office channel on Tuesday, although the North issued criticism over a joint military exercise between Seoul and Washington. 

A Unification Ministry official in Seoul said that the two Koreas had a phone call at 9 a.m. via the liaison hotline. 

The two Koreas have held two phone calls every day since they restored cross-border communications lines on July 27.

Earlier on Tuesday, Kim Yo-jong, the powerful sister of North Korean leader Kim Jong-un, issued a statement blasting South Korea and the United States for conducting a joint military exercise. 

Kim said that South Korea and the U.S. started the drill that further escalates instability and that the North expresses "strong regret over the act of betrayal by South Korea."