North Korea warned on Wednesday of a military response after South Korea joined an anti-proliferation exercise, and said it is no longer bound by the 1953 armistice which ended their war.
A military statement quoted by official media also said the North could no longer guarantee the safety of shipping off its west coast.
It repeated Pyongyang’s position that Seoul’s decision to join the US-led Proliferation Security Initiative (PSI) is tantamount to a declaration of war.
South Korea announced on Tuesday it will become a full member of the PSI initiative to curb trade in weapons of mass destruction.
“Any tiny hostile acts against our republic, including the stopping and searching of our peaceful vessels... will face an immediate and strong military strike in response,” the statement said.
A strident North Korea has reportedly restarted a weapons-grade nuclear plant and staged a mass rally to celebrate its second nuclear test.
The North also announced that South Korea’s decision to participate in an international program aimed at stemming the flow of weapons of mass destruction was equal to a “declaration of war”.