SEOUL: The South Korean and US militaries launched their biggest joint military exercises in years Monday, as North Korea said it conducted submarine-launched cruise missile tests in apparent protest of the drills it views as an invasion rehearsal.

North Korea's missile tests Sunday signal the country likely will conduct provocative weapons testing activities during the US-South Korean drills that are to run for 11 days. Last week, North Korean leader Kim Jong Un ordered his troops to be ready to repel its rivals' 'frantic war preparation moves.'