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

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

North Korea says the region is 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.