North Korea (search) said Thursday it won't give up its nuclear weapons without receiving a reactor for generating power, stalling six-nation talks on Pyongyang's atomic programs.

"We're in a bit of a standoff at this point," said the chief U.S. delegate to the talks, Assistant Secretary of State Christopher Hill (search).

Hill said no progress was made during a 90-minute meeting Thursday because Pyongyang (search) was demanding that it get a reactor before dismantling its nuclear program.

"The basic stumbling block has to do with the issue of providing a light-water reactor," North Korean spokesman Hyun Hak Bong said in the first comment from the delegation since the talks resumed Tuesday.

Still, Hill and other delegates said the talks would continue, with no end date set.

The United States has said giving such a reactor to the North is out of the question, given the cost and the communist nation's history of deceit over its pursuit of nuclear technology to build weapons.

The North was promised two such reactors under a 1994 deal that fell apart in late 2002 after the latest nuclear crisis erupted. Light-water reactors are believed to be less easily diverted for weapons use.

"Providing a light-water reactor is a matter of principle for building trust," Hyun said. "The United States says it cannot give us a light-water reactor no matter what. It is telling us to give up the nuclear (program) first without doing its part."

"This is a problem related to the United States' political will to get rid of its hostile policy toward us and peacefully coexist," he said.

But the North Korean spokesman added that his government still hoped to "solve the nuclear issue peacefully through dialogue."

The North has been offered economic aid, security guarantees from Washington and free electricity from South Korea in exchange for dismantling its nuclear weapons program. The South Korean offer to send electricity to the North could begin delivering power in a few years, helping alleviate chronic energy shortages that have further hampered its already struggling economy.

Hill described the reactor issue as a "nonstarter."

North Korea, "not for the first time, has chosen to isolate itself," Hill said. The country "has a rather sad and long history of making the wrong decision on things."

None of the other countries at the talks, which also include Russia and South Korea, has stepped forward with an offer to foot the estimated $2 billion to $3 billion cost for building a reactor, Hill said, noting it could take up to a decade to be completed.

"There are still great differences on certain issues," Chinese Foreign Ministry spokesman Liu Jianchao said after Thursday's meeting. He said the talks would continue.

The head of Japan's delegation, Kenichiro Sasae, also expressed pessimism, saying the situation was "extremely difficult."

These talks ended a five-week recess after the last session failed to yield an agreement after 13 days of meetings. No end date has been set.

South Korea's top envoy said the conflict wasn't an insurmountable barrier to an agreement, if Washington and Pyongyang show flexibility.

"We know very well what North Korea wants, and we have opened the window of opportunity for North Korea to have a light-water reactor in the future," said Deputy Foreign Minister Song Min-soon.

Song said it was not necessary for that promise to be mentioned explicitly in the statement the six sides are seeking agreement on now.

China also called for the sides to seek compromise, but did not go as far as to openly back the North's stand.

"We think that any legitimate, reasonable, concern or interest of any party deserves careful study and consideration," Chinese Foreign Ministry spokesman Qin Gang said.

Hill said Wednesday that North Korea has used its 25-year-old nuclear program solely to make weapons-grade plutonium for atomic bombs — not for generating electricity.

"Not a single light bulb has been turned on as a result of the nuclear reactor in North Korea," he said, referring to the country's main atomic facility in Yongbyon.

A Washington-based think tank released a satellite photo Wednesday showing that the reactor at Yongbyon has apparently been restarted, noting a steam plume was seen Sunday rising from its cooling tower. The reactor was shut down earlier this year and the North said its fuel rods were removed, a move that would allow it to harvest more weapons-grade plutonium.

The Institute for Science and International Security also released a satellite photo showing activity at the North's 50-megawatt nuclear reactor under construction, including a new road surface and possibly a crane, but said it didn't appear there was large-scale work at the site.