South Korean President Yoon Suk-yeol has instructed security officials to “punish” North Korea for any future “provocations,” saying they must not fear Pyongyang’s nuclear arsenal following a major security breach earlier this week.

“President Yoon told them to punish and retaliate in no uncertain terms in response to any provocation by North Korea, saying that is the most powerful way to deter provocations,” press secretary Kim Eun-hye told reporters, adding that Yoon “emphasized that we must not be fearful or hesitant just because North Korea has nuclear weapons.”

While South Korea responded to the incident on Monday with its own drone flight over the North, the military was unable to shoot down any of the UAVs that crossed the border, with a senior defense official acknowledging that it showed an “insufficiency in the military readiness posture.” Yoon also said preparedness is “greatly lacking,” and reportedly “berated” Defense Minister Lee Jong-sup for the failure to neutralize the trespassing aircraft.

spend $441 million to improve the country’s defenses. The money will be spent over the next five years, including on projects to develop a new signal jammer and an airborne laser weapon to repel drone incursions. The president is set to visit the Agency for Defense Development on Thursday to review preparations for improvements.

Military activity on the Korean Peninsula has seen a significant spike in 2022, with Pyongyang carrying out a record number of weapons tests this year, including multiple intercontinental ballistic missile (ICBM) launches. The South has also conducted a flurry of live-fire exercises alongside the United States in recent months, which the DPRK has repeatedly condemned as rehearsal for an invasion. Nonetheless, Seoul has vowed to respond more aggressively to North Korean actions, with Defense Minister Lee telling lawmakers on Wednesday that he has been ordered to retaliate “even if that means risking escalation.”