South Korea plans to formally notify North Korea and China early next month of its plan to conduct an annual military exercise with the United States that Pyongyang has demanded be called off, a government source said Sunday.The South Korean and US militaries are scheduled to hold the annual Key Resolve command post exercise for two weeks from late February to early March to improve their joint combat readiness and capabilities to deter threats from North Korea.“We will notify China and North Korea of the schedule and purposes of Key Resolve in accordance with international practice,” the source said. “After the Lunar New Year holiday, we will offer explanations through military diplomacy channels and the Military Armistice Commission.”The point of the planned notification is to emphasize that the exercise is an annual defensive drill, the source said, adding that this year’s exercise will be similar in scale to those of previous years and will include maritime maneuvers involving Aegis-equipped destroyers, submarines and guided missile cruisers, state-run (Yonhap) news agency reported.But it won’t involve U.S. aircraft carriers or strategic bombers, the source said.After the Key Resolve exercise, the South and the U.S. plan to hold a field training drill, called Foal Eagle, through the end of April. The exercise will involve a large number of troops from both sides.North Korea has long denounced these maneuvers as a rehearsal for an invasion of the communist nation, though the South and the U.S. have repeatedly said that the drills are defensive in nature.Earlier this month, the North demanded the cancellation of the upcoming joint exercises while proposing that the two Koreas stop military provocations and mutual slandering to improve bilateral relations.South Korea has rejected the demand, saying it will hold the exercises as planned.Last year, North Korea sharply escalated tensions on the divided peninsula as it churned out near-daily war threats against the South and the U.S. in anger over the annual drills.About 28,500 U.S. troops are stationed in South Korea to help defend the ally from North Korea, a legacy of the 1950-53 Korean War that ended in an armistice rather than a peace treaty.