SEOUL, South Korea — North Korea said it will restart all facilities at its Yongbyon nuclear site shut by a 2007 disarmament accord, in the latest sign Kim Jong Un is expanding his atomic weapons program in the face of international censure.

A uranium enrichment plant and a 5-megawatt graphite-rod reactor will resume operations after North Korea’s leadership said it will pursue the twin goals of economic and nuclear development, the Korean Central News Agency said, citing a spokesman of the General Department of Atomic Energy.

The reactor, which generates spent plutonium fuel rods, was closed in 2007 as part of a deal with the United States, South Korea, China, Russia, and Japan to end North Korea’s nuclear ambitions in exchange for energy aid.

Six-nation talks to dissuade the totalitarian regime from developing nuclear weapons and testing missiles failed and haven’t been held since 2008.

Restarting the reactor follows statements by Kim that his country is in a state of war with South Korea and may launch pre-emptive nuclear strikes against the United States, which North Korea has yet to prove it can do.

The Obama administration Monday said it has detected no unusual North Korean troop movements to back up its threats.

“North Korea seems to be stating that it will produce more weapons-grade plutonium and generate energy through enriched uranium,” said Ham Hyeong Pil, research fellow at the Korea Institute for Defense Analyses in Seoul. “It seems to have made this declaration to pressure the U.S. and elicit money through negotiations. In reality, it will take the North at least six months to a year to start running the reactor.”

Stocks Fall

South Korean stocks extended losses following the KCNA report, with the benchmark Kospi index closing down 0.5 percent at 1,986.15. The won fell 0.3 percent to 1,117.98 per dollar.

Restarting the nuclear facilities, “if true, will be extremely unfortunate,” South Korean Foreign Ministry spokesman Cho Tai Young said Tuesday in Seoul, adding his government will keep close watch on the situation.

Kim over the weekend called nuclear weapons development a top priority and reiterated threats to attack the United States and South Korea.

Nuclear arms can “never be abandoned” nor “traded with billions of dollars,” Kim said at a March 31 meeting of the ruling Workers’ Party Central Committee, KCNA reported.