North Korean leader Kim Jong Un approved a plan to prepare standby rockets to target the mainland U.S., the country’s state television said Friday. The move was retailiation for American stealth bombers conducting an exercise over South Korea. “It’s time to settle accounts with the U.S. imperialists,” Kim Jong Un said in a meeting with military leaders, adding that he was preparing for a “merciless strike.” U.S. officials said the North Korean regime has issued a blizzard of threats recently, but that the rocket announcement wouldn't be dismissed as bluster.