NPR correspondent Chris Arnold is based in Boston. His reports are heard regularly on NPR's award-winning newsmagazines Morning Edition, All Things Considered, and Weekend Edition. He joined NPR in 1996 and was based in San Francisco before moving to Boston in 2001.
State media described the drill as aimed at demonstrating the strength and diverse attack means of North Korea's nuclear forces amid deepening tensions with the United States and South Korea
Voting concludes Tuesday in Pennsylvania's presidential, U.S. Senate and U.S. House primary contests. Polls close at 8 p.m. ET. Follow the live results.