Six countries reached a tentative agreement Tuesday on initial steps toward North Korea's nuclear disarmament that could usher in the first concrete progress after more than three years of talks marked by delays, deadlock and the communist country's first nuclear test explosion.

The U.S. envoy to the talks, Assistant Secretary of State Christopher Hill, said the tentative deal on the North's nuclear program had been approved by the U.S. government.

"Yes, we've approved it, to the best of my knowledge we've approved it," Hill said, adding the North Koreans had seen the same text.

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The Chinese said the North Koreans "went over every word of it," Hill said.

The draft agreement contained commitments on disarmament and energy assistance along with "initial actions" to be taken by certain deadlines, Hill said earlier. Working groups will be set up, hopefully in a month, he added.

He declined to give further details of the draft struck after a marathon 16-hour negotiating session.

The New York Times reported that the draft called for North Korea to complete the "permanent disablement" of its main nuclear facilities at Yongbyon within 60 days.

The newspaper said the U.S., South Korea and China would provide aid under the deal. South Korea's Yonhap news agency said the North would receive 500,000 tons of heavy oil and other energy and humanitarian assistance equivalent to that amount.

Left for later discussion would be what to do with the atomic weapons the North now is believed to possess — a half-dozen or more by expert estimates. The deal also reportedly fails to address the uranium enrichment program that Washington accuses North Korea of having.

All six heads of delegations met again Tuesday morning, where they made some "suggestions of technical changes, but the draft was virtually concluded," a South Korean official said on condition of anonymity due to the ongoing process. A full session of negotiators was expected later Tuesday.

The current talks began Thursday on a promising note after the United States and North Korea held an unusual meeting last month in Germany and signaled a willingness to compromise. But negotiations quickly became mired on the issue of how much energy aid the impoverished and isolated communist country would get as an inducement for initial steps toward disarmament.

The agreement could herald the first step toward disarmament since the talks began in 2003. The process reached its lowest point in October when North Korea conducted its first nuclear test explosion, alarming the world and triggering U.N. sanctions.

The draft agreement still must be approved by the other governments in the talks — China, North Korea, Japan, Russia and South Korea.

North Korea did not immediately make any public comment, but South Korea's envoy Chun Yung-woo said he believed the proposal would be acceptable to Pyongyang.

"I am looking forward to hearing good news today. I hope it will be a good day for all of us," he told reporters, adding "no country had raised an objection to the principle" that the costs of the energy aid should be evenly shared.

But Japan's Prime Minister Shinzo Abe said Tuesday that Tokyo cannot give aid to the North because it has failed to properly resolve the issue of abductions of Japanese citizens that it has previously admitted. North Korea has turned over five of the 13 kidnap victims it acknowledged and claims the others died.

Japanese Foreign Minister Taro Aso cautioned an agreement in itself did not signal the long-running nuclear standoff was over.

"This is only the first step, and we still have to see if concrete steps move forward," Aso said in Tokyo.

John Bolton, the former U.S. ambassador to the U.N., harshly criticized the deal and urged President George W. Bush to reject it, saying it made the U.S. look weak.

"I am very disturbed by this deal," he told CNN. "It sends exactly the wrong signal to would-be proliferators around the world: 'If we hold out long enough, wear down the State Department negotiators, eventually you get rewarded,' in this case with massive shipments of heavy fuel oil for doing only partially what needs to be done" to dismantle the nuclear program."

In September 2005, North Korea was promised energy aid and security guarantees in exchange for pledging to abandon its nuclear programs. But talks on implementing that agreement repeatedly stalled on other issues.

Under a 1994 U.S.-North Korea disarmament agreement, the North was to receive 500,000 tons of fuel oil a year before construction was completed of two nuclear reactors that would be able to generate 2 million kilowatts of electricity.

That deal fell apart in late 2002 when the U.S. accused the North of conducting a secret uranium enrichment program, sparking the latest nuclear crisis.

Complete coverage is available in FOXNews.com's North Korea Center.