North Korea

A North Korean traffic policeman stands at an intersection in Kaesong, North Korea.

David Guttenfelder/AP

A North Korean traffic policeman stands at an intersection in Kaesong, North Korea.

A Chinese soldier stands guard at the main entrance door of the Bayi building where US Joint Chiefs Chairman General Martin Dempsey met with Chinese military officials in Beijing on April 23, 2013.  Dempsey was expected to discuss concerns over tensions with North Korea, amongst other bilateral items.

Andy Wong/AFP

A Chinese soldier stands guard at the main entrance door of the Bayi building where US joint chiefs chairman General Martin Dempsey met Chinese military officials in Beijing. Gen Dempsey was expected to discuss concerns over tensions with North Korea. 

A South Korean soldier holding his machine gun runs in front of an advertisement board during an anti-terror drills at Government Complex in Sejong, south of Seoul, South Korea, Wednesday, April 17, 2013. North Korea lashed out anew Tuesday at South Korea over a small public protest in Seoul in which demonstrators burned effigies of the North's leaders, saying it would not hold talks with its southern neighbor unless it apologized for anti-North Korean actions "big and small" and warning that it could take retaliatory measures at any time.

Lee Jin-man/AP

A South Korean soldier holding his machine gun runs in front of an advertisement board during an anti-terror drill at Government Complex in Sejong, south of Seoul, South Korea on Wednesday. North Korea on Tuesday lashed out anew at South Korea over a small public protest in Seoul in which demonstrators burned effigies of the North’s leaders, saying it would not hold talks with its southern neighbour unless it apologised for anti-North Korean actions ‘big and small’ and warning that it could take retaliatory measures at any time.

A man, center, supervises a dancing group  during a mass folk dance in front of the Pyongyang Indoor Stadium in Pyongyang, North Korea, Monday, April 15, 2013. Oblivious to international tensions over a possible North Korean missile launch, Pyongyang residents spilled into the streets Monday to celebrate a major national holiday, the birthday of their first leader, Kim Il Sung.

Alexander F. Yuan/AP

A man, center, supervises a dancing group during a mass folk dance in front of the Pyongyang Indoor Stadium in Pyongyang, North Korea, Monday, April 15, 2013. Oblivious to international tensions over a possible North Korean missile launch, Pyongyang residents spilled into the streets Monday to celebrate a major national holiday, the birthday of their first leader, Kim Il Sung.

South Korean soldiers patrol on the South Korea-controlled island of Yeonpyeong

Jung Yeon-Je/AFP

South Korean soldiers patrol the South Korea-controlled island of Yeonpyeong near the disputed waters of the Yellow Sea at dawn on April 14 2013. The Korean peninsula has been engulfed by escalating military tensions and dire threats of nuclear war ever since North Korea conducted a rocket test in December and a nuclear test in February.

Retired North Korean military members stand at attention during an induction ceremony for children into the Korean Children's Union, the first political organization for North Koreans, held at a stadium in Pyongyang on Friday, April 12, 2013.

David Guttenfelder/AP

Retired military officers of North Korea stand at attention during an induction ceremony for children into the Korean Children’s Union, the first political organisation for North Koreans, held at a stadium in Pyongyang on Friday.

South Korean soldiers of an artillery unit check their gears during a drill as it snows in Hwacheon...South Korean soldiers of an artillery unit check their gears during a drill as it snows in Hwacheon, about 20 km (12 miles) south of the demilitarized zone separating the two Koreas and about 120 km (75 miles) northeast of Seoul April 9, 2013. North Korea warned foreigners in South Korea on Tuesday to quit the country because they were at risk in the event of conflict, the latest threat of war from Pyongyang.  REUTERS/Lee Jae-Won (SOUTH KOREA

South Korean soldiers check their equipment during a drill near the demilitarised zone. Lee Jae-Won/Reuters

South Korean soldiers of an artillery unit check their equipment during a drill as it snows in Hwacheon, about 20 km south of the demilitarised zone separating the two Koreas and about 120 km northeast of Seoul on April 9. North Korea urged foreigners in South Korea on Tuesday to leave the country because they were at risk in the event of conflict, the latest threat of war from Pyongyang.

South Korean army reservists raise their hands to adopt a resolution against North Korea during a rehearsal for their Foundation Day ceremony at a gymnasium in Seoul, South Korea, Friday, April 5, 2013.

South Korean army reservists raise their hands to adopt a resolution against North Korea during a rehearsal for their Foundation Day ceremony at a gymnasium in Seoul, South Korea, on April 5 2013. AP/Ahn Young-joon

About 1,000 reservists denounced North Korea for escalating the threat for war. North Korea has been railing against US-South Korean military exercises that began in March and will continue until the end of April. The allies insist the exercises in South Korea are routine, but the North calls them rehearsals for an invasion and says it needs nuclear weapons to defend itself. 

A US Air Force F-22 stealth fighter jet takes off from the Osan US Air Base in Pyeongtaek on April 3

A US Air Force F-22 stealth fighter jet takes off from the Osan US Air Base in Pyeongtaek on April 3. Yon Hap/AFP

North Korea have blocked access to a key joint industrial zone with South Korea, a sharp escalation in a military crisis that Washington blamed on Pyongyang’s “reckless” behaviour. The US has positioned a warship off the Korean coast as a shield against ballistic missile attack, and also deployed radar-evading F-22 Raptors on Sunday to take part in the annual joint military drills it carries out with South Korea.