North Korean leader Kim Jong Un renewed threats of an “all-out war” as he visited frontline artillery units on his country’s western coast, state media reported on Tuesday.

The Rodong Sinmun daily said Kim on Monday visited a defense unit on Wolnae island and another long-range artillery unit under the North Korean People’s Army’s 641 unit.

The army unit was tasked with targeting South Korean naval forces on Baengnyeong Island, the South’s northernmost island near the maritime border. Wolnae Island lies just 11km from Baengnyeong.

The long-range artillery unit near the border was involved in the North’s shelling of Yeonpyeong Island in November 2010, The Chosunilbo reports.

Kim reportedly told troops in the area to be ready to “throw all enemies into a burning cauldron” as soon as he gives the order, according to reports from the North’s media.

“Kim confidently said the North can turn Baengnyeong Island into a sea of fire,” the report said.

“The reason for my visit is to finalize the order of attacks and the focus of firepower,” Kim was quoted as saying by the Rodong Sinmun, adding: “When I give an order, you should fire the first gunshots in the grand war to unify our homeland.”

Seoul called the move “psychological warfare” meant to agitate the South.

South Korean Defense Ministry spokesman Kim Min-suk said there is no reason to be alarmed by the North’s tactics and told reporters, “It seems that the regime is tightening control internally and trying to pressure South Korea and the US into changing their North Korea policies.”