Pyongyang residents react as they mourn over the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/Kyodo

Pyongyang residents react as they mourn over the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/Kyodo

Pyongyang residents react as they mourn over the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/Kyodo

Pyongyang residents react as they mourn the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. REUTERS/Kyodo

North Koreans cry and scream in a display of mourning for their leader Kim Jong Il at the foot of a giant statue of his father Kim Il Sung in Pyongyang, North Korea, after Kim Jong Il’s death was announced Monday, Dec. 19, 2011. North Korea's news agency reported that he had died at 8:30 a.m. Saturday after having a heart attack on a train, adding that he had been treated for cardiac and cerebrovascular diseases for a long time. He was 69. (AP Photo/APTN)

Pyongyang residents reacts as they mourn over the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. REUTERS/Kyodo

North Koreans mourn the death of their leader Kim Jong Il in Pyongyang on December 21, 2011. North Korea said that millions of grief-stricken people turned out to mourn "Dear Leader" Kim Jong-Il, whose death has left the world scrambling for details about his young successor. AFP PHOTO/Kyodo

Pyongyang residents reacts as they mourn over the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/Kyodo

A woman and her son cry as they mourn the death of North Korean leader Kim Jong-il at a square on Mansu Hill in Pyongyang, in this photo taken by Kyodo on December 19, 2011. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/Kyodo

North Korean men cry as they mourn the death of North Korean leader Kim Jong-il in Pyongyang December 19, 2011 in this picture released by the North's official KCNA news agency on Monday. North Korean leader Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/KCNA

North Koreans mourn in front of a picture of their late leader Kim Jong Il in Pyongyang on December 21, 2011. North Korea said that millions of grief-stricken people turned out to mourn "Dear Leader" Kim Jong-Il, whose death has left the world scrambling for details about his young successor. AFP PHOTO/Kyodo

North Koreans mourn as they pay their respects to their late leader Kim Jong Il in Pyongyang on December 21, 2011. North Korea said that millions of grief-stricken people turned out to mourn "Dear Leader" Kim Jong-Il, whose death has left the world scrambling for details about his young successor. AFP PHOTO/Kyodo

(111220) -- BEIJING, Dec. 20, 2011 (Xinhua) -- Nationals of the Democratic People's Republic of Korea (DPRK) in China mourn the death of DPRK top leader Kim Jong Il at the DPRK embassy in Beijing, capital of China, Dec. 20, 2011. (Xinhua/Liu Weibing) (ry)

North Koreans mourn for deceased leader Kim Jong-il in Pyongyang in this picture released by the North's official KCNA news agency early December 21, 2011. North Korea was in seclusion on Tuesday, a day after it announced the death of its leader Kim Jong-il, as concern mounted over what would happen next in the deeply secretive nation that is trying to build a nuclear arsenal. REUTERS/KCNA

North Koreans mourn for deceased leader Kim Jong-il in Pyongyang in this picture released by the North's official KCNA news agency early December 21, 2011. North Korea was in seclusion on Tuesday, a day after it announced the death of its leader Kim Jong-il, as concern mounted over what would happen next in the deeply secretive nation that is trying to build a nuclear arsenal. REUTERS/KCNA

North Koreans mourn for their deceased leader Kim Jong-il at the Kumsusan Memorial Palace in Pyongyang in this picture taken on December 21, 2011 and released by the North's KCNA news agency on December 23, 2011. Kim Jong-il, who ruled isolated and impoverished North Korea from 1994, died on December 17, 2011, according to the state's media. REUTERS/KCNA

Pyongyang residents react as they mourn over the death of North Korean leader Kim Jong-il in Pyongyang, in this photo taken by Kyodo on December 19, 2011. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/Kyodo

Residents kneel down as they mourn the death of North Korean leader Kim Jong-il during a gathering in a square in Pyongyang in this December 19, 2011 still image taken from video. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/KCNA

Employees of Pyongyang 326 Electric Wire Factory mourn over the death of North Korean leader Kim Jong-il, as they gather in a conference hall in Pyongyang December 19, 2011 in this still image taken from video. Kim Jong-il died on a train trip on Saturday, state television reported on Monday, sparking immediate concern over who is in control of the reclusive state and its nuclear programme. REUTERS/KCNA