No sign of movement of troops or weapons , general says . US defense secretary speaks with South Korean counterpart . U.S. troops in North Korea not on special mission , general say . North Korea conducts nuclear test launch ; West not alarmed .
No sign of movement of troops or weapons , general says . U.S. defense secretary speaks with South Korean counterpart . U.S. troops in South Korea not on special alert , officials say . North Korea conducts missile test launch ; West not alarmed .