North Korean leader Kim Jong Un on Monday ordered the military to perform a controversial drill in the vicinity of a maritime boundary with South Korea.

The move has angered the South Korean government, which believes that the move violates a bilateral military pact between the two countries. The drill was part of Kim's visit to the Changrin Islet.

“He indicated the target for Gun 2 of the coastal artillery company on combat duty and gave an order to fire,” the state-run Korean Central News Agency said about Kim's involvement in the drill. The troops “fully showed their gun firing skills they cultivated in their day-to-day training to delight the Supreme Leader,” the agency added.

The South Korean Defense Ministry quickly rebuked the drills, saying it violated a military agreement between the two countries.

“We call on North Korea to immediately stop all military actions in border areas that risk heightening military tensions, and to fully comply with the pact,” South Korean defense spokesperson Choi Hyun-soo told reporters.

The artillery firing is likely a way to raise attention amid stalled nuclear negotiations between Pyongyang and Washington. Earlier this month, U.S. Defense Secretary Mark Esper announced that the U.S. would postpone joint drills with South Korea, in a goodwill effort towards North Korea. Pyongyang has frequently denounced the drills, believing that they are part of a preparation for an invasion.

North Korea and the U.S. have held diplomatic talks several times over the last two years, with North Korea wanting reduced sanctions in exchange for possible denuclearization. The last time North Korean and U.S. negotiators have met to discuss the issue was in Sweden in early October, with talks falling through on the first day of negotiations.

President Trump and Kim have had a strong relationship, meeting in Hanoi in February and Singapore in June 2018 to discuss a possible denuclearization deal, though no concrete agreement has been achieved.

Pyongyang has set a deadline for the end of the year for a nuclear deal, threatening the U.S. to offer concessions or it will break off negotiations entirely.