Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)

Photo provided by Korean Central News Agency (KCNA) on March 19, 2013 shows a drill of the People's Army of the Democratic People's Republic of Korea (DPRK). (Xinhua/KCNA)