South Korean army K-55 self-propelled artillery vehicles move during a military exercise near the demilitarized zone between the two Koreas in Paju, South Korea, Sunday, Jan. 11, 2015. North Korea has told the United States that it is willing to impose a temporary moratorium on its nuclear tests if Washington scraps planned military drills with South Korea this year, the North's official news agency said Saturday. (AP Photo/Ahn Young-joon)