SEOUL, South Korea - North Korea vowed Tuesday to restart all mothballed facilities at its main Yongbyon nuclear complex, adding to tensions already raised by near daily warlike threats against the United States and South Korea.

The reactor was shut down in 2007 as part of international nuclear disarmament talks that have since stalled.

A spokesman for the General Department of Atomic Energy said that the facilities to be restarted are a graphite-moderated 5 megawatt reactor, which generates spent fuel rods laced with plutonium and is the core of the Yongbyon nuclear complex. The reactor, when fully running, is capable of churning out one atomic bomb worth of plutonium — the most common fuel in nuclear weapons — a year.

The move will boost fears in Washington and among its allies about North Korea's push for nuclear-tipped missiles that can reach the United States, technology it is not currently believed to have.

Pyongyang conducted its third nuclear test in February, prompting U.N. sanctions that have infuriated its leaders and led to the current tensions. The country has since declared that making nuclear arms and a stronger economy are the nation's top priorities.

North Korea added the 5-megawatt, graphite-moderated reactor to its nuclear complex in 1986 after seven years of construction. The country began building a 50-megawatt and a 200 megawatt reactor in 1984, but their construction was suspended under a 1994 nuclear deal with Washington.

North Korea has long said that the reactor operation is aimed at generating electricity. It takes about 8,000 fuel rods to run the reactor. Reprocessing the spent fuel rods after a year of reactor operation could yield about 7 kilograms of plutonium — enough to make at least one nuclear bomb, experts say.

Loading Slideshow...
  • North Koreans gather at a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • North Korean army officers punch the air as they chant slogans during a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • CORRECTS DATE PHOTO TAKEN - North Koreans gather during a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • North Koreans march through Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. Soldiers and students are shown holding placards that read: “Reunification of the motherland,” left, and “Let’s rip apart the puppet traitors,” center. (AP Photo/Jon Chol Jin)

  • North Koreans gather at a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • North Koreans punch the air during a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. The placard reads: "U.S. forces, get out!" (AP Photo/Jon Chol Jin)

  • North Koreans punch the air during a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • North Koreans gather during a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • North Koreans punch the air during a rally at Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. (AP Photo/Jon Chol Jin)

  • University students punch the air as they march through Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. Placards read: “Let’s crush the puppet traitor group” and “Let’s rip the puppet traitors to death!” (AP Photo/Jon Chol Jin)

  • University students march through Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. Placards in the plaza read: “Rifles and bombs,” “Sledgehammers of revenge” and “Do-or-die battle.” (AP Photo/Jon Chol Jin)

  • University students punch the air as they march through Kim Il Sung Square in downtown Pyongyang, North Korea, Friday, March 29, 2013. Tens of thousands of North Koreans turned out for the mass rally at the main square in Pyongyang in support of their leader Kim Jong Un's call to arms. Placards read: “Let’s crush the puppet traitor group” and “Let’s rip the puppet traitors to death!” (AP Photo/Jon Chol Jin)