South Korea vows fast response to North; U.S. deploys stealth jets

SEOUL (Reuters) - South Korea will strike back quickly if the North stages any attack, the new president in Seoul warned on Monday, as tensions ratcheted higher on the Korean peninsula amid shrill rhetoric from Pyongyang and the U.S. deployment of radar-evading fighter planes.

North Korea says the region is on the brink of a nuclear war in the wake of United Nations sanctions imposed for its February nuclear test and a series of joint U.S. and South Korean military drills that have included a rare U.S. show of aerial power.