(CNN) -- North Korea threatened to conduct a nuclear test and more ballistic missile tests if the U.N. Security Council doesn't withdraw its condemnation of Pyongyang's rocket launch earlier this month, the state-run Korean Central News Agency reported.
A photo released by North Korea's official Korean Central News Agency showing the recent rocket launch.
The U.N. Security Council "should promptly make an apology for having infringed the sovereignty of [North Korea] and withdraw all its unreasonable and discriminative 'resolutions' and decisions adopted against [North Korea]," a spokesman for the North's Foreign Ministry said in a statement.
"The measures will include nuclear tests and test-firings of intercontinental ballistic missiles," the unidentified spokesman said.
The statement also said Pyongyang will start building a light-water nuclear power plant and begin production of nuclear fuel.
The Security Council condemned the April 5 rocket launch as a violation of a 2006 resolution that bans North Korea's ballistic missile activity.
North Korea, angered by the Security Council's unanimous vote, has threatened to walk away from the six-party talks aimed at disarming the country of nuclear weapons. It has said it will restore its disabled nuclear reactor.
The six-party talks -- involving China, Japan, North Korea, Russia, South Korea and the United States -- have been aimed at persuading North Korea to scrap its nuclear program.
North Korea has begun reprocessing fuel rods, its Foreign Ministry said Saturday, according to state-run media.
"The reprocessing of spent fuel rods from the pilot atomic power plant began as declared in the Foreign Ministry statement dated April 14," a ministry spokesman said.
"This will contribute to bolstering the nuclear deterrence for self-defense in every way to cope with the increasing military threats from the hostile forces."