North Korea is planning to unload fuel rods at its Yongbyon reactor within the next three months in what would be a significant boost to its nuclear weapons capability, an American scholar said Saturday.

During a meeting this past week in Pyongyang, Selig Harrison said that North Korean Vice Foreign Minister Kim Kye Gwan told him that the communist nation would unload the rods "beginning this fall, and no later than the end of the year."

Removing the fuel rods is "a significant new development because it underlines that North Korea is enhancing its weapons capability," Harrison, director of the Asia program at the Washington-based Center for International Policy, told reporters shortly after arriving from a four-day stay in North Korea.

The Yongbyon reactor has been at the center of U.S. concerns about North Korea's nuclear weapons program. The reactor's spent fuel rods can be mined for plutonium, which then can be used to construct nuclear bombs.

North Korea has stayed away from six-nation nuclear talks — which include China, Japan, Russia, South Korea and the U.S. — since last year in anger over U.S. financial restrictions against the North for its alleged complicity in counterfeiting and money laundering.

North Korea has insisted it won't return to the talks unless the U.S. drops its sanctions. Pyongyang claims to have nuclear weapons and further stoked regional tension in July by test-firing a series of missiles over international objections, drawing condemnation from the U.N. Security Council.

During this trip, Harrison said he met with a vice president of the Supreme People's Assembly, Kim Yong Dae, a senior military figure, Lt. Gen. Ri Chan Bok as well as with the foreign minister.

The North Korean officials would neither confirm nor deny the country was planning to conduct a nuclear test, Harrison said.