Negotiators reported slow progress in talks on disabling North Korea's nuclear program, saying Friday they were trying to hash out details of how the reclusive Communist regime should fulfill a pledge to close down its facilities.

North Korea has agreed to declare its nuclear programs and disable them, but has not been able to agree with the five other countries involved in the talks on how to define those terms.

"We are looking at scope of disablement, we are looking how big the declaration needs to be — it's supposed to be all nuclear programs, so we want to make sure we get all nuclear programs," U.S. Assistant Secretary of State Christopher Hill told reporters.

"So we are going to have to look at all these questions. It's not easy and the reason it's not easy is it's never been done before," he said.

Under a February agreement, North Korea will be provided with 1 million tons of heavy fuel oil, or the monetary equivalent in other aid and assistance. In return, North Korea agreed to shut down its main nuclear reactor — which it did in July — and then declare and ultimately dismantle all its nuclear programs.

The talks — which also include host China, South Korea, Japan and Russia — have dragged on for four years, during which time North Korea successfully detonated a nuclear device.

China had been expected to circulate a draft statement Friday on what disarmament steps needed to be completed by the end of the year. Hill said that did not happen, but that North Korea gave a date for when it would give its declaration to the others.

It would happen "much before" the end of the year, he said, but added that he could not reveal the specific timing.

"This is a new stage, it's never been done before ... so obviously we are taking some time at it," Hill said. "We still have a ways to go."

Another issue during talks Friday was North Korea's goal of being removed from a U.S. list of countries that sponsor terrorism, which would make it eligible for various benefits.

Hill said the topic came up during a bilateral discussion, but did not provide details. Various officials and lawmakers in the United States have said it is much too early for that to happen.

Delegates from South Korea and Japan gave negative assessments on the progress of the talks, held at the Diaoyutai State Guesthouse in Beijing.

Chun Yung-woo, the chief South Korean delegate, said there were still gaps over what North Korea was intending to do and what the other countries wanted.

"I don't bring good news," Chun told reporters. "At this stage, it's not the time we can say the prospect for the results of the talks is optimistic or negative."

Japanese envoy Kenichiro Sasae told reporters "the chances of reaching an agreement are quite slim."

"On the whole, North Korea and the other parties, including the U.S., have big differences in their opinions and demands, so the situation is not looking very optimistic," he said.

A sticking point has been Tokyo's focus on the issue of Japanese citizens kidnapped by the North.

North Korea admitted in 2002 that it had abducted 13 Japanese citizens in the 1970s and 80s and allowed five to return home, saying the others were dead. Many Japanese believe more victims remain in the communist country, and the government has refused to contribute aid to North Korea under the February agreement.

The latest round of six-party discussions are scheduled to end Sunday.