Tensions are at their highest in years, with the North and the U.S.-backed South demonstrating their military preparedness.
North Koreans attend a rally in support of North Korean leader Kim Jong-un's order to put its missile units on standby in preparation for a possible war against the U.S. and South Korea, Pyongyang, March 29, 2013.
University students punch the air as they march through Kim Il Sung Square in downtown Pyongyang, North Korea, March 29, 2013.
South Korean soldiers prepare for a military exercise, Paju, north of Seoul, South Korea, March 29, 2013.
A U.S. Air Force B-2 stealth bomber flies near Osan U.S. Air Base in Pyeongtaek, south of Seoul, South Korea, March 28, 2013.