US and South Korea hold military drills amid tension with North

This photo provided by the North Korean government shows what it says is a submarine called the 8.24 Yongung ship (North Korea/AP)

The South Korean and US militaries launched their biggest joint military exercises in years, 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 on Sunday signal the country likely will conduct provocative weapons testing activities during the US-South Korean drills that are to run for 11 days.