The phone conversation between Song and Mattis took place on Saturday, according to the ministry.
"Defense Minister Song Young-moo spoke about the success of the historic highest-level talks between the South and the North, and said that,… by honestly implementing the agreements between the leaders of the South and the North, [South Korea] will be multiplying its efforts for denuclearization of the Korean Peninsula and building peace," the statement read.
The statement comes a few days after the historic inter-Korean summit, which took place at the truce village of Panmunjom.
During the meeting, the leaders of the two Koreas signed a joint declaration, agreeing to cease hostile activities against each other. They also agreed to take measures to support international efforts aimed at denuclearization the peninsula and proceed with reunion programs for the separated Korean families.