North Korean leader Kim Jong Un’s sister, Kim Yo Jong, condemned U.S.-South Korea military drills and warned of possible retaliation in a new statement released on Tuesday.

Kim Yo Jong called the computer-simulated military exercises “a serious challenge” and demanded that they stop entirely, accusing South Korea of making excuses about the reduced size and changed format of the annual joint readiness drills, according to the state-run Korean Central News Agency (KCNA).

Instead of traditional military drills, Washington and Seoul opted for a computerized, COVID-19-friendly “command post exercise (CPX),” which startedon March 8. At the time, a