Following news reports Monday that North Korea could soon conduct its sixth nuclear test, just days after it carried out another such exercise, the Japanese government is bracing for the possibility of more provocations by Pyongyang.

South Korean Defense Ministry spokesman Moon Sang-gyun told a news briefing Monday that the North is ready to carry out another nuclear test at any time at the Punggye-ri site.

North Korea has so far conducted five tests at the site near its northeast coast. Moon said the North might use another unused tunnel at the test site.