CAMP HUMPHREYS, South Korea — U.S. and South Korean forces sharpened their nuclear response plans this month with a tabletop exercise and Seoul’s first-ever nuclear weapons effects training, as tensions with North Korea persist.

The five-day tabletop exercise, Iron Mace 25-1, wrapped up Friday, according to the South’s Joint Chiefs of Staff. It followed a two-day course in Seoul led by U.S. Forces Korea, according to an April 16 command news release.

Few details were disclosed about either event. USFK spokesman David Kim, citing operational security, referred questions back to the releases on Tuesday. A Joint Chiefs spokesman did not immediately respond to a request for further information.

The nuclear effects training focused on how South Korea’s conventional forces would support U.S. nuclear operations as part of the allies’ strategic deterrence, USFK spokesman Col. Ryan Donald said in the release. The course also covered the skills needed to operate in a nuclear environment.

Six staff members from South Korea’s Strategic Command, two from the Ministry of National Defense, and five from Combined Forces Command took part, along with two instructors from the U.S. Army Nuclear and Countering Weapons of Mass Destruction Agency Employment Advisory Team.

During Iron Mace, held later in Seoul, participants discussed ways to bolster extended deterrence — the U.S. commitment to defend South Korea, including with nuclear weapons if necessary — according to the Joint Chiefs release.

The training and exercise were agreed to last June by the Nuclear Consultative Group, a U.S.-South Korea body formed to strengthen join nuclear planning.

Combining South Korean conventional weapons with U.S. nuclear operations “substantively strengthens the allied deterrence and response capabilities” against North Korea’s growing nuclear and missile threat, the Defense Department said.