North Korea says it carried out an underground nuclear test Tuesday . It is the third nuclear test it has carried out since 2003 . It comes after new UN sanctions for North Korea 's December satellite launch . Experts say it 's unknown how close the country is to being able to launch a nuclear warhead .
North Korea says it carried out an underground nuclear test Tuesday . It is the third nuclear test Pyongyang has carried out since 2006 . It comes after new U.N. sanctions for North Korea 's December satellite launch . Experts say it 's unknown how close the North is to being able to launch a nuclear warhead .