The U.S. Department of Defense said on the Thursday, "We believe that North Korea has made preparations to conduct nuclear tests at the Punggye-ri nuclear testing site within this month." This could be seen as a warning that North Korea could carry out nuclear tests around next Wednesday, the date the Korean War Armistice Agreement was signed.
Martin íManus, a Pentagon spokesman, responded to The Dong-A Ilbo's inquiry on the same day as follows, “The U.S. assessment of the possible nuclear tests is consistent with a recent statement from North Korea. We have shared this information with our allies and will work closely with our allied partner countries.” Earlier on Monday, the Rodong Sinmun, the official newspaper of the Central Committee of the Workers' Party of Korea, claimed that "our self-defense nuclear deterrence is reliable and effective."
Since the Pentagon has specified a possible testing time to be 'within this month', some think that the ROK and U.S. intelligence agencies may have detected a new move at the Punggye-ri nuclear testing site. In particular, the U.S. Strategic Command in charge of nuclear command and control missions focused on North Korea's use of small tactical nuclear weapons at its first closed-door meeting last May, the Wall Street Journal (WSJ) reported on Wednesday.
The WSJ reported that at the meeting, there were concerns about North Korea's use of tactical nuclear weapons to induce concessions from South Korea and the United States in the early stages of a potential armed conflict on the Korean Peninsula. There was also an analysis that if North Korean leader Kim Jong Un deemed that South Korea and the United States would engage in a “beheading operation,” Kim will opt to use nuclear weapons.