WASHINGTON (AP) – Secretary of State Condoleezza Rice leveled a warning Monday that “it would be a very serious matter and indeed a provocative act” if North Korea tested a long-range ballistic missile.

Rice’s remarks came after Bush administration officials said North Korea has apparently finished loading fuel into a ballistic missile, the latest signs that the reclusive communist state will soon test a weapon that could reach the United States.

Testing would abrogate several North Korean commitments and “it would be taken with utmost seriousness,” Rice said at a news conference.

U.S. intelligence indicates that the long-range missile, believed to be a Taepodong-2, is assembled and fully fueled, said two officials, who requested anonymity because the information comes from sensitive intelligence methods.

Rice cited North Korea’s pledge of a missile moratorium in 1999 and its reiteration of the moratorium in 2002. She said North Korea also agreed in six-party negotiations not to test long-range missiles.

She said the United States was working very closely with its allies on the problem, but did not say what might be done if North Korea tested the missile.

The fueling reportedly gives the North a launch window of about a month. Unlike other preparatory steps the United States has tracked, the fueling process is very difficult to reverse, and most likely means the test will go ahead, one senior administration official said.

The precise timing is unclear, the official said.

The United States assumes North Korea would only perform a test, not fire the weapon as an act of war, and could claim afterward that it was launching a space mission, the official said. That would still be considered a violation of the moratorium North Korea has observed since 1999, the official said.

The test would probably take place over water, not land, and occur during daylight hours, the official said. North Korea is 14 hours ahead of the East Coast.

The United States would probably know “within seconds” that a launch had taken place, the official said.

At the Pentagon, spokesman Bryan Whitman would not comment on whether U.S. intelligence indicates that the North Koreans are preparing for a possible missile launch. Whitman said the Pentagon uses the term “launch,” instead of test, because of the possibility that the North Koreans have hostile intent.

Whitman would not say whether the United States might activate its missile defense systems in the event of a North Korean launch.

Although the three-stage Taepodong 2 could theoretically reach the U.S. West Coast, most experts think North Korea is still a long way off from perfecting the technology that would make the missile accurate and able to carry a nuclear payload.

Robert Zoellick, the departing deputy secretary of state, said North Korea’s fueling of the missile became known only recently.

At U.N. headquarters in New York, U.S. Ambassador John Bolton said he was holding preliminary consultations with Security Council members on steps that might be taken if North Korea fires a missile, “because it would obviously be very serious.”

“But we don’t really know what the North Korean intentions are at this point, so I think we need to wait for the event,” he said.

“Obviously the first preference is that the North Koreans not light the missile off,” Bolton said, noting that the United States, Japan, Australia, South Korea and other countries had urged North Korea to abandon any missile firing.

Aboard Air Force One with President Bush, White House spokesman Tony Snow declined specific comment on reports that the fueling is complete.

“North Korea has imposed a moratorium on launching missiles,” Snow said. “We hope it will continue that moratorium and we hope it also will abide by commitments it made,” last year to dismantle nuclear weapons and renounce further development of them.

Snow said President Bush has made some of the administration’s recent telephone calls to more than a dozen heads of state about the indications of a coming launch.

Snow would not identify which leaders spoke with Bush. He also said U.S. officials have talked directly with North Korean representatives in New York, a reference to a diplomatic channel through the North’s United Nations mission. Snow would not disclose contents of the discussion, but diplomats from numerous countries have been telling the North Koreans to back off any plans for a missile test launch.

North Korea referred to its missile program for the first time Monday, but has not said it intends to perform the test.

A North Korean state television broadcast, monitored in Seoul, South Korea, cited a Russian editorial on the missile and said the North “has the due right to have a missile that can immediately halt the United States’ reckless aerial espionage activity.”

The North has repeatedly complained in recent weeks about alleged U.S. spy planes watching its activities.

A test would be the North’s first significant missile launch since a 1998 test that send a missile over Japanese territory. Pyongyang began a self-imposed test moratorium in 1999, even while continuing separate development of a nuclear weapons program.

North Korea says it needed nuclear weapons and a such potential delivery systems as a missile to counter what it claims are U.S. intentions to invade or topple the government. The United States has repeatedly denied any plans to invade.