President Yoon Suk-yeol receives a briefing on military readiness from top military commanders at his office in Seoul on Jan. 1 in this photo released by his office. Yonhap

President Yoon Suk-yeol ordered military commanders Sunday to punish any North Korean provocations without fail with a "firm determination not to avoid going to war," an official said.

Yoon made the call in virtual talks with Joint Chiefs of Staff Chairman Gen. Kim Seung-kyum and other commanders, as the North's state media reported that North Korean leader Kim Jong-un has called for an "exponential" increase in the country's nuclear arsenal while naming the South "our undoubted enemy."

"Our military should certainly punish any enemy provocations with a firm determination not to avoid going to war," he was quoted by his spokesperson, Lee Jae-myoung, as saying at the talks at the underground national crisis management center at the presidential office in Seoul.

"I call on you to bear in mind that our troops' firm mental readiness posture and realistic training can only guarantee strong security," he added.