WASHINGTON — U.S. spy agencies confirmed North Korea’s recent nuclear test on Monday, even as Secretary of State Condoleezza Rice declared that U.N. sanctions prove the world is united in opposing Pyongyang’s nuclear ambitions.
Meanwhile, U.S. spy satellites have detected suspicious vehicle and people activity near the site of North Korea’s nuclear test that may signal preparations for another test, U.S. television networks reported on Monday.
Rice said that the strong opposition reflected by U.N. sanctions should be a warning to Iran. Rice leaves Tuesday morning for an Asian trip that is expected to be dominated by the nuclear issue. She will visit Japan, South Korea, China and Russia.
“The Iranian government is watching, and it can now see that the international community will respond to threats from nuclear proliferation,” said Rice, who added that she believes the Security Council will begin working on a sanctions resolution against Iran this week. “The Iranian government should consider the course that it is on.”
Rice dismissed skepticism among some in Washington about China’s commitment to tough action against its communist neighbor following the sanctions resolution adopted unanimously by the U.N. Security Council on Saturday.
“I am not concerned that the Chinese are going to turn their backs on their obligations,” she said. “I don’t think they would have voted for a resolution that they did not intend to carry through on.”
U.S. officials said they could not be certain of what the North Koreans were doing in the area surveilled by the satellites, but the activity there could be preparations for a second nuclear blast, ABC News said, with no further details.
Negroponte confirms test
National Intelligence Director John Negroponte’s office released the government’s first definitive confirmation that North Korea tested a nuclear device on Oct. 9.
“The explosion yield was less than a kiloton,” the statement said, smaller than many experts had expected.
“Analysis of air samples collected on October 11, 2006, detected radioactive debris which confirms that North Korea conducted an underground nuclear explosion,” the statement continued.
Each kiloton is equal to the force produced by 1,000 tons of TNT. An intelligence official said the North Korean device was believed to be roughly the equivalent of 200 tons of TNT, suggesting to analysts that it was probably a partial failure. Experts in and out of government had anticipated a detonation of at least several thousand tons.
At the State Department, Rice said the world “has responded calmly and firmly” to the test.
“North Korea cannot endanger the world and then expect other nations to conduct business as usual in arms or missile parts,” Rice said, previewing her message for the Asia trip. “It cannot destabilize the international system and then expect to exploit elaborate financial networks built for peaceful commerce.”
The United States, North Korea and seven other nations are now believed to have nuclear arms. Yet North Korea’s unpredictable behavior and its history of trading military arms and components makes its nuclear advancements particularly worrisome to its neighbors and the international community.
The U.S.-sponsored United Nations resolution on North Korea demands that Pyongyang eliminate nuclear weapons. But it also rules out military action against the country, as the Russians and Chinese demanded.The nuclear-armed planet
It calls on countries to block North Korea from receiving equipment or materials to build weapons of mass destruction and other advanced weaponry. It also would clamp down on travel for North Koreans involved in the weapons program and freeze many of the international assets of people or businesses connected to that program.
After the resolution was unanimously passed, North Korea’s U.N. ambassador accused council members of a “gangster-like” action that neglects the nuclear threat posed by the United States.
Worries over escalation
Rice acknowledged international concerns of escalating the crisis and said she would address that on her trip. Countries in the region worry that the collapse of North Korea’s government could send millions of refugees streaming toward their borders. South Koreans also worry about a conventional attack by their neighbor.
“We have no desire to ratchet up conflict,” Rice said. “But we’ll have some discussions on precisely how this will be carried out.”
While China has been inspecting cargo trucks headed for its communist ally, its U.N. ambassador indicated its inspectors will not board ships to search for suspicious equipment or material, raising questions about how strictly it and South Korea will enforce the U.N. resolution. Both countries have significant trade relations with North Korea, whose economy is perpetually on the verge of collapse.
“Actions are more powerful than words, and we expect the actions will be powerful,” White House spokesman Tony Snow said.
Second test would not be a surprise
Earlier Monday, many in the U.S. government said they would not be surprised if North Korea were to attempt a second nuclear test. The decision to test is considered a political one, and officials say North Korea will be monitoring action at the United Nations and elsewhere.
Rice said a new test “would further deepen the isolation of North Korea.”
A key clue on the nature of North Korea’s nuclear detonation — its first — came from air samples collected by the Air Force’s WC-135 Constant Phoenix, a jet designed to collect particles and gases after a nuclear test. Samples are rushed back to labs in the United States for study before they lose their radioactive properties.
The first reading last Tuesday was negative, but a test on a second sample collected Wednesday was positive, according to the government intelligence official.
Certain gases present in air sample
When scientists evaluate air samples, they are looking for the presence of certain materials and gases such as xenon, which is released after the fission of uranium or plutonium.
While xenon is one indicator, “you’d like to get a leakage where you have many more fission products — mixed in with plutonium or highly enriched uranium,” said David Albright, president of the Washington-based Institute for Science and International Security and a former U.N. weapons inspector.
Albright, who has followed North Korea’s program for two decades, believes its scientists are trying to miniaturize a nuclear device to put it atop a missile. While the test was likely a partial fizzle, those scientists may not have been after a large nuclear blast, he said.
“It doesn’t mean that it failed by any means,” Albright said. “If it failed, you would see no yield at all.”
The Associated Press and Reuters contributed to this report.