Obama calls North Korea's nuclear test a 'provocation'
13 February 2013 Last updated at 03:27 GMT
President Obama has used his annual State of the Union speech to condemn the latest nuclear test by North Korea.
Mr Obama described the move as an act of "provocation", saying it would only serve to isolate Pyongyang from the rest of the world.
Speaking in the House of Representatives, Mr Obama said America would lead the world in taking "firm action'' in response to such threats.