WASHINGTON — President Bush urged Americans last night to steel themselves for a prolonged, unconventional, largely covert war against an elusive network of enemies, and he issued a challenge to every foreign government.

"Either you are with us or you are with the terrorists," said Bush, addressing a united Congress and a stricken nation.

He described a global war against terrorism, issuing an ultimatum to the Taliban leadership in Afghanistan to immediately hand over Osama bin Laden and vowing that "from this day forward, any nation that continues to harbor or support terrorism will be regarded by the United States as a hostile regime."

For the first time, he listed the specific demands that the United States is making of the Taliban, who have provided bin Laden his base of operations and formed a close alliance with his group, al Qaeda:

Defining them as "demands," Bush called on the Taliban to:

• "Deliver to United States authorities all the leaders of al Qaeda who hide in your land."

• "Release all foreign nationals — including American citizens — you have unjustly imprisoned." Two Americans are among eight foreign-aid workers imprisoned in Afghanistan for allegedly preaching Christian beliefs to Muslims.

• "Close immediately and permanently every terrorist-training camp in Afghanistan and hand over every terrorist, and every person in their support structure, to appropriate authorities."

• "Give the United States full access to terrorist-training camps, so we can make sure they are no longer operating."

Those demands go far beyond any concessions the Taliban have agreed to consider, and the militant Afghan regime appeared unlikely to agree. Yesterday, authorities in Kabul said only that they would ask bin Laden whether he was willing to leave the country.

"These demands are not open to negotiation or discussion," Bush said bluntly. "The Taliban must act and act immediately. They will hand over the terrorists, or they will share in their fate."

The president also said he will create a new Cabinet-level position, the Office of Homeland Security, to oversee domestic defenses against terrorism. He said he will name Pennsylvania Gov. Tom Ridge, a longtime Republican ally, as its first chief.

To roars of bipartisan support, Bush, who was interrupted by applause 30 times during his 34-minute speech, promised that the United States will punish and ultimately vanquish the terrorist forces that executed the deadliest attack ever on U.S. soil Sept. 11. But he pleaded for patience from the nation in waging war against a sprawling, shadowy foe vastly different from any before.

"Tonight we are a country awakened to danger and called to defend freedom," Bush said. "Our grief has turned to anger, and anger to resolution. Whether we bring enemies to justice, or bring justice to our enemies, justice will be done."

British Prime Minister Tony Blair joined the audience in the Capitol. He has pledged that Britain will stand "shoulder to shoulder" with the United States.

Also in the audience was New York Mayor Rudolph Giuliani and New York Gov. George Pataki, leaders of the city and state that have suffered the most, and Lisa Beamer, whose late husband, Todd, is believed to have helped attack the hijackers of the airliner that crashed in Pennsylvania.

Bush described a diverse array of military strikes executed over time, ranging from airstrikes that will have highly visible results to covert actions that will not. He made plain that the immediate target is suspected terrorist mastermind bin Laden, the al Qaeda network he heads and the Taliban leadership if it responds with anything less than complete cooperation to his demands.

But Bush said he would not stop there. "Our war on terror," he said, "will not end until every terrorist group of global reach has been found, stopped, and defeated."

That passage was one of several carefully crafted to maximize international support for a U.S.-led campaign. Specifying that he was aiming only at groups of "global reach," would alleviate concerns that he was proposing war on Palestinian liberation groups, for instance, a move that would have little support in the Middle East. He mentioned several times that the terrorists he was targeting practice a "fringe form of Islamic extremism" and that he was not labeling all Muslims as enemies.

The address came on a day Giuliani — who won praise from Bush — revised sharply upward the official number of people missing and presumed dead in the collapse of the World Trade Center towers to 6,333; the number of confirmed dead is 241.

The magnitude of the crisis detonated by the terrorist attacks was illustrated by several unusual elements of the address:

Vice President Dick Cheney did not attend, watching instead from an undisclosed location protected by the Secret Service, to ensure that no tragedy befell both the president and the vice president.

House Majority Leader Dick Armey, R-Texas, also was absent, a precaution to preserve congressional leadership should disaster strike, though he is not in the line of succession to the presidency.

In addition, Democratic leaders decided not to respond as the political opposition to the speech. The order of the day: Solidarity.

"We want America to speak with one voice tonight," said House Minority Leader Dick Gephardt, D-Mo.

The speech came as the U.S. military was rapidly revving its war machinery, dispatching ships and aircraft to the Middle East and calling up troops for what top officials said would be a military campaign of many months, or even years, duration.

"And tonight a few miles from the damaged Pentagon," he said, "I have a message for our military: Be ready. I have called the armed forces to alert, and there is a reason."

Bush described al Qaeda, as being to terror "what the Mafia is to crime" — but with a goal not of making money but of "remaking the world and imposing its radical beliefs on people everywhere."

Bush pointed to the influence of bin Laden and his network in Afghanistan, but made it clear it was the terrorists — not the people of that rugged land — that are his targets. "Afghanistan's people have been brutalized," he said.

He also asked Americans to prevent the zeal for retribution from curdling into misguided hatred. "The enemy of America is not our many Muslim friends; it is not our many Arab friends," he said. "Our enemy is a radical network of terrorists and every government that supports them."

Information from Knight Ridder Newspapers and the Los Angeles Times is included in this report.