Pyongyang demanded an end to joint military exercises by the U.S. and South Korea

North Korea demanded that the U.S. and South Korea stop large-scale military exercises, calling them a provocation that could lead to “increased retaliation” by Pyongyang.

“The situation on and around the Korean Peninsula has once again entered the phase of a serious confrontation of ‘force against force’ due to the endless reckless actions of the United States and South Korea,” the DPRK Foreign Ministry said in a statement reported by the official news agency CTAC.

The U.S. and South Korea began one of the largest joint air exercises Monday, in which hundreds of warplanes from both sides will conduct training attacks 24 hours a day for most of the week.

Operation Vigilant Storm will run through Friday. The U.S. Air Force said about 240 warplanes will take part, flying about 1,600 sorties.