Pentagon Chief Spokesperson Dana W. White provided the following readout:
On September 5, Secretary of Defense Jim Mattis spoke with the Republic of Korea (ROK) Minister of National Defense Song Young-moo to discuss North Korea's test of a nuclear device on September 2. Secretary Mattis assured Minister Song that the United States remains ironclad in its commitment to the defense of the ROK. He further emphasized that any threat to the United States, its territories, or its allies will be met with a massive, effective, and overwhelming military response. Secretary Mattis and Minister Song discussed avenues for improving bilateral, trilateral, and regional defense cooperation in light of the threat posed by North Korea and to maintain peace and stability in Northeast Asia and the broader Asia-Pacific region.