North Korea may have built a second, secret facility for producing weapons-grade plutonium as part of efforts to enlarge its nuclear arsenal, US officials said. The disclosure, first reported by The New York Times and confirmed by US officials in Washington, could lead to an escalation in the festering diplomatic showdown between North Korea and the United States over Pyongyang?s atomic weapons program. White House officials, while not confirming the report, insisted that Washington would continue to work with its allies in the region to press Pyongyang to reverse course. ?We do not discuss intelligence matters so I?m not going to get into specifics about the report,? White House spokesman, Scott McClellan told reporters traveling with President George W. Bush in Texas.

But he cited a series of ?escalatory steps? by North Korea since it stated publicly last year that it had a covert nuclear weapons program, from the expulsion of international inspectors to its assertion that it had begun reprocessing spent fuel rods, a move he singled out as a ?particular concern.?

?North Korea has no legitimate use for plutonium harvested during this procedure,? McClellan said. ?And reprocessing to recover plutonium is a clear indication that North Korea is intent on enlarging its nuclear arsenal despite repeated calls from the international community for North Korea to reverse the provocative steps it has taken and end its nuclear weapons program,? he added.

North Korea declared to Washington in recent weeks it had completed reprocessing 8,000 spent nuclear fuel rods, or enough to make a half dozen or so nuclear weapons.

Emission of toxic gas

US officials have said they cannot verify that claim but, according to The New York Times, they confirm that sensors on North Korea?s borders have begun detecting elevated levels of krypton 85, a gas emitted as spent fuel is converted into plutonium. Computer analyses tracking the gases as they are blown across the Korean Peninsula appeared to rule out North Korea?s main nuclear plant at Yongbyon, strongly suggesting that the gas originated from a second, secret plant, perhaps buried in the mountains, the Times said. The findings represent the first time evidence has emerged that a second plant may be in operation in North Korea. Officials with the CIA and the State Department declined to comment.

China has been attempting to arrange a resumption of talks on North Korea but the United States has turned down Beijing?s overtures for a multilateral forum for the discussions with the possibility of direct bilateral talks between Washington and Pyongyang. The United States went to war against Iraq over Saddam Hussein?s yet-to-be-found weapons of mass destruction. But so far Washington still wants a peaceful solution leading to North Korea?s verifiable dismantling of its nuclear weapons program, while not ruling out a military option.

Adam Entous