North Korea's Kim Jong Un says H-bomb test self-defensive step against U.S.

A U.S. Air Force B-52 (R) flies over Osan Air Base in Pyeongtaek, South Korea, January 10, 2016. REUTERS/Kim Hong-Ji

SEOUL (Reuters) - The United States deployed a B-52 bomber on a low-level flight over its ally South Korea on Sunday, a show of force following North Korea's nuclear test last week.

North Korean leader Kim Jong Un maintained that Wednesday's test was of a hydrogen bomb and said it was a self-defensive step against a U.S. threat of nuclear war.