North Korea test-fires missiles amid US carrier deployment.

North Korea fired two short-range ballistic missiles on Monday, marking its seventh missile test this month, as the US and South Korea began joint military exercises. The launches came as the USS Nimitz and its battle group arrived in the region for drills with South Korean warships. The North's weapons tests and the US-South Korea joint military exercises have intensified in a cycle of tit-for-tat. The South Korean and Japanese militaries denounced the latest launches as a serious provocation threatening regional peace. North Korea has launched more than 20 ballistic and cruise missiles on 11 occasions this year.