South Korea and U.S. start stepped-up military drills

SEOUL -- South Korea and the U.S. started an expanded version of key annual military exercises on Monday as part of the allies' efforts to counter the nuclear threat posed by North Korea.

The drills, called Freedom Shield, are held annually and involve live, virtual and field-based training, with the involvement of personnel from various military services. They are aimed at "enhancing interoperability and elevating combat readiness."