WASHINGTON - North Korea has failed to fully disclose its nuclear operations and weapons programs as it promised, the State Department said yesterday.

"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," the department's deputy spokesman, Tom Casey, said in a statement.

North Korea agreed in talks with the United States, China, Japan, Russia and South Korea to disable its plutonium-producing facilities and declare all nuclear programs by the end of 2007 in order to get aid. Casey said the United States would work with the other governments to "urge North Korea" to fulfill the Oct. 3 agreement.

The accord North Korea signed requires it to disclose all its nuclear operations and disable its Yongbyon nuclear reactor, which produces weapons-grade plutonium, in exchange for 1 million metric tons of fuel oil or equivalent energy aid and normalized relations with the United States and Japan. The deadline was today.

President Bush got involved in the matter with a direct letter to President Kim Jong Il on Dec. 1, and North Korea provided a "verbal reply" through diplomats in New York.

Progress on nuclear disarmament would clear "a pathway toward better political relations between the United States and North Korea," Secretary of State Condoleezza Rice said Dec. 21.

North Korea wants the United States to remove it from the State Department's list of countries that sponsor terrorism. The communist nation was put on the list in 1988 after its agents were implicated in the bombing of a South Korean passenger jet the year before that killed all 155 people on board.

The six-nation talks, which began in 2003, gained urgency after North Korea detonated its first nuclear device in October 2006.

Under the accord, North Korea must include the number of nuclear warheads produced and the amount of processed plutonium in the declaration.

North Korea began disabling its Yongbyon reactor, fuel reprocessing plants, and a fuel fabrication plant under the supervision of U.S. inspectors in November. It also committed not to transfer nuclear materials, technology or knowhow beyond its borders.