The United States and South Korea are discussing deploying more U.S. "strategic assets" to the region after North Korea's atomic test last week
However, it refuses to restore U.S. nuclear arms to the South.
North Korea said it tested a hydrogen bomb on Wednesday, displeasing China, its main ally, and the United States.
In a show of force and support for allies in the region following North Korea's nuclear test, the US sent a nuclear-capable B-52 bomber based in Guam on a flight over South Korea.
