Pentagon Press Secretary Peter Cook provided the following statement:
Today U.S. Secretary of Defense Ash Carter called Japan Minister of Defense Gen Nakatani to discuss the recent North Korea nuclear test. Secretary Carter and Minister Nakatani both agreed that the nuclear test by North Korea is an unacceptable and irresponsible act that undermines regional security and stability. Minister Nakatani stated that the test was a clear violation of the United Nation's Security Council resolutions and condemned the act. Secretary Carter agreed with this view and commended the high level of coordination between the United States and Japan after the test. The secretary noted that utilizing the Alliance Coordination Mechanism under the 2015 Guidelines for U.S. -Japan Defense Cooperation exemplifies this close cooperation.
Secretary Carter reaffirmed steadfast U.S. defense commitments to Japan and allies in the region. Both agreed that trilateral cooperation with the Republic of Korea is critical to deterrence and maintaining peace and security in Northeast Asia and beyond, and they reiterated their commitment to continue close trilateral cooperation and information sharing.