North Korea confirmed on 17 August that it has resumed plutonium production and said it has no plans to stop nuclear tests as long as perceived threats from the USA continue. "We have reprocessed used nuclear fuel rods removed from a graphite-moderated reactor," the Atomic Energy Institute, which holds jurisdiction over North Korea's main nuclear facilities at the Yongbyon complex, said in a written interview with Kyodo News. In its first-ever response to foreign media questions, the institute also said North Korea has been producing highly enriched uranium necessary for nuclear arms and power "as scheduled”.

The comments from the Atomic Energy Institute mark the first clear confirmation by North Korea of renewed reprocessing since it vowed in 2013 to restart the 5MWe reactor and other nuclear facilities at the key complex that were shut down under an agreement reached in the six-party talks in 2007.

The research centre did not rule out the possibility of conducting a fifth nuclear test and claimed that North Korea has already succeeded in "minimising, making lighter and diversifying" nuclear weapons.

When the denuclearization talks, involving China, Japan, North Korea, Russia, South Korea and the United States, effectively collapsed in 2009, Pyongyang also said it had begun reprocessing used nuclear fuel rods to produce plutonium.

But at that time the nuclear reactor was not in operation and it was believed that North Korea used stockpiled used fuel.

There had been some indications of renewed activity at the nuclear complex, cited by foreign officials and security experts based on satellite imagery in recent months. In February, US intelligence chief James Clapper said in a report to Congress that North Korea could recover plutonium from the reactor's spent fuel within weeks to months. Analysts at the US-Korea Institute at Johns Hopkins University warned last year North Korea could have up to 100 nuclear weapons by 2020 in a worst-case scenario. Now that the reactor has been reactivated it is believed North Korea could produce about 6 kilograms of plutonium a year, which is enough to manufacture more than one nuclear bomb.

At a ruling party congress in May, North Korean leader Kim Jong Un made it clear that he will stick to his signature policy of pursuing nuclear armament and economic development simultaneously. At the same time, Kim told the congress   that the highest priority must be placed on solving electricity shortages and improving the living standards of his people, promoting the use of nuclear power. In the interview, the North Korean institute unveiled a plan to construct a light-water reactor NPP. To begin with, it said, North Korea will build a 100MWe light-water reactor for experimental use. North Korea's nuclear ambitions continue even after the UN Security Council imposed new, tougher sanctions on North Korea in March. The measures were put in place following its fourth nuclear test in January and a rocket launch using banned ballistic missile technology in February.