WASHINGTON - President Bush called Wednesday for stiff sanctions on North Korea for its reported nuclear test and asserted that the United States has "no intention of attacking" the reclusive regime.
North Korea's No. 2 leader threatened to conduct more nuclear tests if the United States continued what he called its "hostile attitude."
Secretary of State Condoleezza Rice said the United States would not attack North Korea, rejecting a suggestion that Pyongyang may feel it needs nuclear weapons to stave off an Iraq-style U.S. invasion.
In its first formal statement since the test, North Korea said it could respond to U.S. pressure with "physical" measures.
"If the U.S. keeps pestering us and increases pressure, we will regard it as a declaration of war and will take a series of physical corresponding measures," the North's Foreign Ministry said in a statement carried by the official Korean Central News Agency. The statement didn't specify what those measures could be.
Japan planned to impose a total ban on North Korean imports and prohibit its ships from entering Japanese ports, a news report said. The sanctions will also expand restrictions on North Korean nationals entering Japan, the country's public broadcaster NHK said.
The sanctions, which also expand restrictions on North Korean nationals entering Japan, are to be announced following an emergency security meeting headed by Prime Minister Shinzo Abe later Wednesday, according to NHK.
Cabinet spokesman Hiroshi Suzuki confirmed a security meeting was scheduled, but refused to discuss its agenda. He said sanctions, if approved, could take effect immediately.
Along the razor-wired no-man's-land separating the divided Koreas, communist troops on the North's side were more boldly trying to provoke their Southern counterparts: spitting across the demarcation line, making throat-slashing hand gestures, flashing their middle finger and trying to talk to the troops, said U.S. Army Maj. Jose DeVarona of Fayetteville, N.C., adding that the overall situation was calm.
It appeared to be business as usual on the streets of North Korea's capital. Video by AP Television News showed people milling about Kim II Sung square and rehearsing a performance for the 80th anniversary of the "Down with Imperialism Union."
Kim Yong Nam, second to North Korean leader Kim Jong Il, told Japan's Kyodo News agency that further nuclear testing would hinge on U.S. policy toward the communist government.
"The issue of future nuclear tests is linked to U.S. policy toward our country," Kim was quoted as saying when asked whether Pyongyang will conduct more nuclear tests.
"If the United States continues to take a hostile attitude and apply pressure on us in various forms, we will have no choice but to take physical steps to deal with that," Kyodo quoted him as saying.
South Korea's defense minister said that Seoul could enlarge its conventional arsenal to deal with a potentially nuclear-armed North Korea.
"If North Korea really has the (nuclear) capabilities, we will improve and enlarge the number of conventional weapons as long as it doesn't violate the principle of denuclearization," Defense Minister Yoon Kwang-ung told parliament.
"We will supplement (our ability) to conduct precision strikes against storage facilities and intercept delivery means, while also improving the system of having military units and individuals defend themselves," he said.
Scientists and other governments have said Monday's underground test has yet to be confirmed, with some experts saying the blast was significantly smaller than even the first nuclear bombs dropped on Japan during World War II.
North Korea appeared to respond to that Wednesday, saying in its statement that it "successfully conducted an underground nuclear test under secure conditions."
In rare direct criticism of the communist regime from Seoul, South Korean President Roh Moo-hyun said that the security threat cited by North Korea is exaggerated or nonexistent.
"North Korea says the reason it is pursuing nuclear (weapons) is for its security, but the security threat North Korea speaks of either does not exist in reality, or is very exaggerated," Roh said, according to South Korea's Yonhap news agency.
He spoke even as South Korea's military was checking its readiness for nuclear attack, Yonhap said. The Joint Chiefs of Staff told Defense Minister Yoon Kwang-ung that the military needed an improved ability to respond to such an attack, including state-of-the-art weapons capable of destroying a nuclear missile, the report said.
Rice said President Bush has told the North Koreans that "there is no intention to invade or attack them. So they have that guarantee. ... I don't know what more they want."
Rice told CNN Tuesday that Bush "never takes any of his options off the table. But is the United States, somehow, in a provocative way, trying to invade North Korea? It's just not the case."
The top U.S. general in South Korea said that American forces are fully capable of deterring an attack from the North despite the communist nation's claim of a nuclear test.
"Be assured that the alliance has the forces necessary to deter aggression, and should deterrence fail, decisively defeat any North Korean attack against" South Korea, U.S. Army Gen. B.B. Bell said in a statement to troops. "U.S. forces have been well trained to confront nuclear, biological and chemical threats."
About 29,500 U.S. troops are deployed in the South, a remnant of the 1950-53 Korean War that ended in a cease-fire that has never been replaced by a peace treaty.
Bell said the seismic waves detected after the claimed test were still being analyzed and that it had not been yet determined if they indicated a successful nuclear test.
A media report that North Korea may have conducted a second nuclear test rattled nerves Wednesday, but the Japanese government said there was no indication that a test had taken place.
NHK reported around 8:30 a.m. that unidentified government sources were saying that "tremors" had been detected in North Korea.
South Korean and U.S. seismic monitoring stations said that they hadn't detected any activity indicating a second test, and White House spokesman Blair Jones said the United States had detected no evidence of additional North Korean testing.
At the United Nations, China agreed to punishment of North Korea but not severe sanctions backed by the U.S., which it said would be too crushing for its impoverished communist ally.
Beijing is seen as having the greatest outside leverage on North Korea as a traditional ally and top provider of badly needed economic and energy aid.
The United States asked the U.N. Security Council to impose a partial trade embargo including strict limits on Korea's weapons exports and freezing of related financial assets.
All imports would be inspected too, to filter materials that could be made into nuclear, chemical or biological weapons.
Pyongyang has demanded one-on-one talks with Washington and has threatened to launch a nuclear-tipped missile if the U.S. doesn't comply.
Washington insists on the so-called six-party format, where Russia, China, South Korea and Japan have joined the United States in talking to North Korea.