A mock Scud-B missile of North Korea, right, and other South Korean missiles are displayed at Korea War Memorial Museum in Seoul, South Korea, Sunday, May 19, 2013. (AP Photo/Ahn Young-joon)
A mock Scud-B missile of North Korea, right, and other South Korean missiles are displayed at Korea War Memorial Museum in Seoul, South Korea, Sunday, May 19, 2013. (AP Photo/Ahn Young-joon)
A mock Scud-B missile of North Korea, right, and other South Korean missiles are displayed at Korea War Memorial Museum in Seoul, South Korea, Sunday, May 19, 2013. (AP Photo/Ahn Young-joon)
South Korean soldiers look through binoculars at a military checkpoint in Paju, South Korea, near the border village of Panmunjom, on Sunday, May 19, 2013. The South Korean military on Sunday beefed up its monitoring of North Korea and is maintaining a high-level of readiness to guard against provocations by the North. (AP Photo/Ahn Young-joon)
South Korean soldiers look through binoculars at a military checkpoint in Paju, South Korea, near the border village of Panmunjom, on Sunday, May 19, 2013. The South Korean military on Sunday beefed up its monitoring of North Korea and is maintaining a high-level of readiness to guard against provocations by the North. (AP Photo/Ahn Young-joon)
A South Korean man watches a TV news reporting missile launch conducted by North Korea, at a Seoul Train Station in Seoul, South Korea, Saturday, May 18, 2013. North Korea fired three short-range guided missiles into its eastern waters on Saturday, a South Korean official said. It routinely tests such missiles, but the latest launches came during a period of tentative diplomacy aimed at easing tensions. The letters at a screen read " Fired three short-range guided missiles." (AP Photo/Ahn Young-joon)
A South Korean man watches a TV news reporting missile launch conducted by North Korea, at a Seoul Train Station in Seoul, South Korea, Saturday, May 18, 2013. North Korea fired three short-range guided missiles into its eastern waters on Saturday, a South Korean official said. It routinely tests such missiles, but the latest launches came during a period of tentative diplomacy aimed at easing tensions. The letters at a screen read " Fired three short-range guided missiles." (AP Photo/Ahn Young-joon)
** FILE ** This 1988 photo provided by Bobby Lee shows Kenneth Bae (right) and Mr. Lee together when they were freshmen at the University of Oregon. Bae, detained for nearly six months in North Korea, has been sentenced to 15 years of "compulsory labor" for unspecified crimes against the state, Pyongyang announced on Thursday, May 2, 2013. (AP Photo/The Register-Guard, Bobby Lee)
** FILE ** In this March 11, 2013, photo released by the Korean Central News Agency (KCNA) and distributed March 12, 2013, by the Korea News Service, North Korean leader Kim Jong-un greets military personnel at a long-range artillery sub-unit of KPA Unit 641 during his visit to front-line military units near the western sea boarder in North Korea near the South's western border island of Baengnyeong. (AP Photo/KCNA via KNS)
