North Korean state media said Kim Jong Un's regime is reviewing a plan to send its army into the Demilitarized Zone separating the country from South Korea.
"Our army is keeping a close watch on the current situation in which the north-south relations are turning worse and worse, and getting itself fully ready for providing a sure military guarantee to any external measures to be taken by the Party and government," the Korean Central News Agency said in an English-language statement early Tuesday local time.
The announcement follows rising tensions with Seoul since two activist groups sent anti-Kim leaflets by balloon across the border into North Korea early this month. That prompted Kim's younger sister to issue an unusual statement saying that it was "high time" to break ties with South Korea.
The sister, Kim Yo Jong, said the next action against the "enemy" would come from the army, raising memories of a decade ago, when North Korea shelled a South Korean island, killing four, and was suspected of torpedoing the South Korean warship, killing 46 sailors.
South Korean President Moon Jae-in tried to defuse tensions by seeking to cancel the licenses of the two groups _ Fighters for Free North Korea and KeunSaem _ over the leaflets. That effort drew criticism from Human Rights Watch, whose Asia director, Phil Robertson, called the move "a blatant violation of freedom of association that cannot be justified with vague appeals to border security and relations with the North."