A South Korean investigation that concluded North Korea was to blame for landmine blasts inside the Demilitarised Zone last month was a violation of sovereignty, Pyongyang said Tuesday, warning of "sure punishment".
The statement from the North's foreign ministry came hours after Seoul said it was considering measures to force an apology over the blasts, which injured three South Korean soldiers.
A joint South Korea-UN investigation whose findings were released Monday concluded that the landmines had been placed inside the Demilitarised Zone (DMZ) by North Korean forces about a year ago, something Pyongyang has denied.
Seoul called on the nuclear-armed North to remove any other mines planted on the southern side of the Military Demarcation Line that runs through the DMZ, the heavily fortified frontier that has divided the Korean Peninsula since the 1953 armistice.
The North Korean foreign ministry on Tuesday called the investigation results a "grave provocation never to be overlooked and a wanton violation of our sovereignty that deserves sure punishment".
The statement carried by state media went on to label the landmine accusations a "premeditated farce" that created a "new danger of war".
"If a jackboot or a spark of fire from (South Korea) goes even a millimeter beyond the border to violate our territory, the border guard forces of (North Korea) will take an immediate and powerful counteraction," it said.
Seoul's military said earlier it was weighing unspecified actions aimed at forcing an apology from Pyongyang.
"We are not ruling out any options or prejudging anything when it comes to additional measures," defence ministry spokeswoman Chung Bin-na told reporters Tuesday.
Landmine incidents in the DMZ have previously heightened tensions between the two Koreas, which remain technically at war.
In 2015, two South Korean soldiers were seriously wounded in a landmine blast on the southern side of the DMZ, with one losing both legs.
Seoul concluded at the time that North Korean troops had crossed the Military Demarcation Line to plant the mines, an accusation Pyongyang denied.
Since 2024, Pyongyang's military has laid mines and built anti-tank barriers along the frontier as part of efforts to permanently seal it off.
During the operation, North Korea also blew up the northern sections of inter-Korean roads no longer in use.
In its Tuesday statement, the North Korean foreign ministry argued that the latest blast was being used by Seoul "to brand our fortification of the southern border... as a 'military invasion' and delay" it.