A U.S. marine attends a winter military drill in Pyeongchang, about 180 km (112 miles) east of Seoul February 7, 2013. North Korea has vowed to conduct more rocket and nuclear tests in response to a U.N. censure for its launch of a long-range missile launch in December. On Tuesday, it vowed "stronger" but unspecified actions in addition to the test. REUTERS/Lee Jae-Won (SOUTH KOREA - Tags: MILITARY) Published: Úno. 7, 2013, 9:49 dop. | Foto: Reuters