SEOUL — South Korean and US troops began naval drills Monday in a show of force partly directed at North Korea amid signs that Pyongyang will follow through on a threat to conduct its third atomic test.
The region has also seen a boost in diplomatic activity since last month, when North Korea announced it would conduct a nuclear test to protest UN Security Council sanctions toughened after a satellite launch in December that the United States and others say was a disguised test of banned missile technology.
Pyongyang’s two previous nuclear tests, in 2006 and 2009, occurred after it was slapped with increased sanctions for similar rocket launches. As it issued its most recent punishment, the Security Council ordered North Korea to refrain from a nuclear test or face ‘‘significant action.’’
State media said Sunday that at a high-level Workers’ Party meeting, leader Kim Jong Un issued ‘‘important’’ guidelines meant to bolster the army and protect national sovereignty. North Korea did not elaborate, but Kim’s guidelines probably refer to a nuclear test and suggest Pyongyang appears to have completed procedural steps and is preparing to conduct a nuclear test soon, said South Korean analyst Hong Hyun-ik.
‘‘We assess that North Korea has almost finished preparations for conducting a nuclear test anytime and all that’s left is North Korea making a political decision’’ to do so, South Korean Defense Ministry spokesman Kim Min-seok told reporters Monday.