US carrier, S. Korea warships start new drills amid tensions

In this image taken from video, South Korean Air Force's F15K fighter jets prepare to take off Tuesday in an undisclosed location in South Korea. (South Korean Defense Ministry via AP)

SEOUL, South Korea — The nuclear-powered aircraft carrier USS Ronald Reagan launched a new round of naval drills with South Korean warships on Friday, a day after North Korea fired more ballistic missiles and flew warplanes in an escalation of tensions with its rivals.