INTERVIEW: N. Korea capable of overwhelming U.S. homeland missile defense: expert

TOKYO - North Korea has greatly advanced its nuclear and missile capabilities since its first nuclear test 20 years ago, potentially to a level that could overwhelm the United States' homeland missile defense and create challenges for its Asian allies, according to a former U.S. intelligence analyst.

"North Korea's nuclear capabilities have grown exponentially in the type, number, and sophistication of its nuclear weapons as well as the missiles to convey them against South Korea, Japan, and the United States," Bruce Klingner, senior fellow at the Maureen and Mike Mansfield Foundation, said in a recent written interview with Kyodo News.