North Korea warns of 'nuclear war' as US-South Korea drills increase.

North Korea has accused the US and South Korea of pushing tensions to the brink of nuclear war through their joint military drills, vowing to respond with "offensive action". The US and South Korea have been conducting a series of annual springtime exercises since March, including air and sea drills involving a US aircraft carrier and B-1B and B-52 bombers, and their first large-scale amphibious landing drills in five years. North Korea has reacted furiously to the exercises, calling them a rehearsal for invasion.