A 79-year-old man was arrested Monday for defacing the stone base of Gwanghwamun Gate at Seoul’s Gyeongbokgung Palace with black marker, writing “Letter to the People and the World” followed by “President Trump,” authorities said.

The inscription, spanning about 1.7 meters across, was discovered by a palace staff member during a morning patrol and reported to police, who detained the suspect at the scene.

Conservation experts from the National Palace Museum used laser equipment to remove the graffiti, which had penetrated the stone’s surface, with officials expecting the work to be completed by the end of the day.

The incident comes less than two years after a high-profile vandalism case at the palace in late 2023, which cost over 130 million won to repair and led to pledges of tighter security.

Cultural Heritage Administration chief Heo Min vowed “strict action” against those who damage heritage sites, saying such acts “will not be tolerated.”

Authorities said they plan to bill the suspect for the cost of the restoration work under cultural heritage preservation laws.