SEOUL, South Korea - North Korea showed no signs of meeting its deadline today for declaring all of its nuclear programs, a key component of its agreement to disarm in exchange for economic aid.

The United States expressed disappointment and urged the North to meet its commitments. But there was no indication that North Korea would immediately face any sanction over the delay - suggesting countries involved in negotiating the agreement were reluctant to raise tensions after a year of progress in the long-standing dispute.

The communist country promised in October to disable its main nuclear reactor at Yongbyon, north of Pyongyang, and give a full accounting of its nuclear programs by Dec. 31 in return for energy aid and political concessions.

The North shut down the plutonium-producing facility in July and disablement work is under way in cooperation with U.S. experts.

But diplomats have said the North is likely to miss the year-end deadline for disablement because a key step - removing fuel rods from the reactor - could take several months. South Korean Foreign Minister Song Min-soon has said there would also be problems in meeting the deadline for disclosure.

There was no immediate comment from North Korea today. Last week, a North Korean official complained of delays in the delivery of economic aid and said the country would have no choice but to slow disablement.

Song, however, said the disablement work was going well.

The United States, which has said it was not aware of delays in delivering aid to the North, criticized the country's failure to disclose its nuclear programs.

"It is unfortunate that North Korea has not yet met its commitments by providing a complete and correct declaration of its nuclear programs and slowing down the process of disablement," State Department deputy spokesman Tom Casey said yesterday.