The U.S. now has evidence of radioactivity at N. Korea test site, indicating it did carry out nuclear test, U.S. official says.

U.S. pushes for NK sanctions vote

U.S. ambassador to U.N. John Bolton talks to reporters.
With the United States pushing for an early vote at the United Nations, diplomats seek to hammer out language on a resolution that would impose sanctions on North Korea in response to its claimed nuclear test.

FULL STORY

• U.S. 'detects North Korea radioactivity'
• Timeline: Pyongyang's nuclear development Video
• CNN Access: Arms race greater danger than terror