The North's Foreign Ministry said Tuesday it took the measure because Washington has failed to remove the country from its list of terror sponsors as a reward for disabling the facilities.
The ministry said in a statement the suspension took effect Aug. 14 and it has notified countries involved in international talks on its nuclear programs.
Pyongyang has been disabling the facilities under a disarmament-for-aid deal reached last year.
The halt in disarmament progress came a week after North Korea lashed out against U.S.-South Korea military exercises and warned it would boost its "war deterrent" against military threats.
A spokesman for North Korea's Foreign Ministry said last Wednesday the North "will increase its war deterrent in every way as long as the U.S. and its followers continue posing military threats to it."
The reference to its "war deterrent" usually refers to the communist nation's nuclear weapons program.
That warning came just two days day after South Korea and the U.S. launched Ulchi Freedom Guardian, an annual computer-simulated war game.
On Sunday, North Korea claimed the joint military exercises were a rehearsal for an attack against it and warned it would repel any aggression.
"The army and people of (North Korea) will never remain an onlooker to the U.S. military and the South Korean bellicose forces staging frantic anti-(North Korea) war moves," the North's official Korean Central News Agency quoted Gen. Kim Jong Gak as saying at a meeting in its capital.
"Should the U.S. imperialists and their following forces misjudge (North Korea's) will and act rashly," North Korea's people and army "will mercilessly wipe out the aggressors to the last man," Kim said.
The harsh North Korean rhetoric was not new, but came three days after South Korea and the U.S. ended the military drills.
The drills involved 56,000 South Korean troops and 10,000 U.S. soldiers in South Korea and abroad, and were aimed at preparing the South Korean government to retake wartime command of its forces from Washington in 2012.
Despite repeated denials from Seoul and Washington, North Korea has denounced the drills as a preparation for an attack on the communist country.
North Korea and the U.S. are in the midst of a dispute over how to verify the North's declared nuclear programs under an aid-for-disarmament deal.
North Korea has accused the U.S. of delaying its removal from a U.S. terror blacklist. The U.S. has said it will drop North Korea from the list only after it agrees to a full nuclear verification plan.