North Korea could miss nuclear deadline: Seoul

SEOUL (Reuters) - North Korea could miss a year-end deadline to fully account for its nuclear arms program, South Korea said on Thursday, while a separate report cited the North's unhappiness at the pace of energy aid.

North Korea reached a deal with regional powers to disable its aging, plutonium-producing nuclear plant and release an inventory of its atomic activities by the end of the year in exchange for aid.

"We have been targeting the end of December but it might go past that," said Foreign Minister Song Min-soon. "Progress in the declaration in particular is slower in comparison to other parts."

North Korea, which since November has been disabling its Soviet-era nuclear complex, feels it has not received energy aid in a timely manner as called for in a six-nation disarmament deal, Japan's Kyodo news agency quoted a North Korean foreign ministry official in Pyongyang as saying.

"We have no choice but to take measures to adjust (the pace of disablement)," said the official, Hyun Hak-bong.

In Washington, U.S. State Department spokesman Tom Casey said he was "not aware that there is any substantive problem with those deliveries" and had not heard of Pyongyang's complaints.

"As to what the North Koreans will or will not do, it's the obligation of all parties to honor their commitments, and we intend to honor ours and we certainly hope they'd honor theirs as well," he said.

In a separate report, a North Korean official told U.S. nuclear negotiator Christopher Hill this month that Pyongyang had about 66 pounds (30 kg) of plutonium, the Tokyo Shimbun said on Thursday, citing unidentified sources in the United States and South Korea.

Hill has said the United States believes secretive North Korea has produced about 50 kg of plutonium, which proliferation experts said conservatively is enough for six to eight weapons.

U.S. and South Korean officials have said the disablement process at the Yongbyon nuclear facility has been going smoothly.

Officials from the two countries have called on the communist state to answer U.S. suspicions it had a secret program to enrich uranium for weapons, which analysts said might be slowing the declaration.

If Pyongyang gives a full accounting of its nuclear programs, the United States is expected to drop it from a U.S. list of state sponsors of terrorism, which imposes economic and other sanctions. (Reporting by Jon Herskovitz in Seoul, Isabel Reynolds in Tokyo and Paul Eckert in Washington; Editing by Doina Chiacu)