South Korean and U.S. troops began naval drills Monday, Feb 4, in a show of force partly directed at North Korea amid signs that Pyongyang will soon carry out a threat to conduct its third atomic test, The Associated Press reports.

South Korean and U.S. militaries kicked off three-day exercises off the Korean Peninsula's east coast that involve live-fire exercises, naval maneuvers and submarine detection drills.

South Korea's Joint Chiefs of Staff said the maneuvers are part of regular joint military training that the allies had scheduled before the latest nuclear tensions began. But the training, which involves a nuclear-powered American submarine, could still send a warning against possible North Korean provocation, a South Korean military official said, requesting anonymity because of department rules.

North Korean state media described the drills as a joint exercise for a preemptive attack on the country. North Korea has said similar things when South Korea and the U.S. conducted other drills; the allies have repeatedly said they have no intention of attacking the North.