U.S. Heeds North Korea on Nuke Claims

North Korea's claim that it has reprocessed 8,000 spent nuclear fuel rods must be taken seriously, U.S. officials said Tuesday.

"Reprocessing is only for the purpose of harvesting plutonium to make weapons — a clear indication that North Korea is bent on enlarging its nuclear arsenal," State Department spokesman Richard Boucher said Tuesday.

North Korean diplomats told State Department official Jack Pritchard last week in New York that the nation had completed reprocessing 8,000 spent nuclear fuel rods, which are used to produce weapons-grade fissile material to make nuclear bombs. The United States also has multiple intelligence sources confirming that the North Koreans have been actively reprocessing at their Yongbyon (search) nuclear plant, the facility U.S. officials say is the possible center of North Korea's uranium reprocessing efforts.

A Pentagon official also confirmed to Fox News that U.S. intelligence has detected traces of the uranium byproduct "Krypton 85" (search) in the air near North Korea's Yongbyon nuclear facility.

The White House insisted Tuesday that it still wants to seek a diplomatic solution to the standoff with Pyongyang through a multilateral approach involving China, South Korea and Japan, but repeated that the United States will not tolerate an expanding nuclear weapons program.

"We will not submit to blackmail or grant inducements to the north to live up to its obligations," said White House press secretary Scott McClellan. "North Korea has a clear choice between two paths. The international community has made clear that continued pursuit of nuclear weapons will only lead to further isolation and a deteriorating situation for the regime in Pyongyang."

The intelligence community believes that North Korea already has at least one nuclear bomb and possibly two or three. With the reprocessing, North Korea is in a position to add to that arsenal.

"If they go flat-out, they could reprocess one bomb a month in the next five or six months," said Joe Cirincione, a nuclear analyst.

Meanwhile, former Defense Secretary William Perry warned that the United States and North Korea are drifting toward war, and the United States is losing control of the situation.

Interviewed by The Washington Post, Perry, well-respected for his knowledge of North Korean issues, said he is concerned that terrorists may be able to purchase a North Korean nuclear device and plant it in a U.S. city.

"The nuclear program now underway in North Korea poses an imminent danger of nuclear weapons being detonated in American cities," he told the Post.

Perry said the Bush administration could have and should have addressed the growing North Korean problem six months ago, a criticism echoed Tuesday by the ranking member of the Senate Foreign Relations Committee.

"It is a serious mistake — there is no policy in this administration toward North Korea, and it is the clear and present danger we face at the moment," said Sen. Joseph Biden, D-Del.

Pentagon officials raised some eyebrows at Perry's remarks, with one saying the former defense secretary was "a bit strong." Still, officials concede that the situation is getting more serious by the week.

Asked if he agreed with Perry's remarks that the North Korea situation is out of control, McClellan said, "It's a serious matter."

But with the administration's commitment to diplomacy, a Chinese special envoy's visit with North Korean leader Kim Jong Il (search) in Pyongyang on Monday was seen as a positive diplomatic development.

"The only way to get this problem solved is to have all of these people at the table, and I think China is especially critical," said former CIA operations officer Peter Brookes.

Even so, as the North Koreans continue to produce nuclear material, Cirincione said time is running out.

"I think the next step is for them to actually test one, and that could be the provocation that actually gets us into a military conflict," he said.

As for whether military options remain viable, McClellan said, "The president never takes options off the table."

Fox News' Bret Baier, James Rosen and Kelly Wright contributed to this report.