WASHINGTON (AP) — The White House rejected a proposal by Islamic clerics on Thursday that Osama bin Laden be allowed to leave Afghanistan voluntarily. As President Bush prepared to address Congress, the Army's civilian leader said the military was bracing for "sustained land combat operations."

The clerics' suggestion that bin Laden be allowed to leave on his own volition "does not meet America's requirements," said White House spokesman Ari Fleischer. "It's time for action and not words."

Nine days after the suicide hijacking attacks that left more than an estimated 5,000 dead or missing in New York and Washington, Bush planned a 9 p.m. EDT address to Congress and the nation to unite Americans for a long battle.

With U.S. military forces on the move, Army Secretary Thomas E. White told reporters a deployment order signed by Defense Secretary Donald Rumsfeld includes Army as well as Air Force troops.

"We are ready to deliver it across the whole array of force structure — heavy, light, airmobile, airborne, special operations," White said.

Stocks fell sharply yet again on fears of adverse economic fallout. Federal Reserve Chairman Alan Greenspan acknowledged that economic activity virtually ground to a halt after the Sept. 11 terrorist attacks.

But, he told a congressional panel that the country's long-term prospects remained strong.

"An enormous effort will be required on the part of many to cope with the human and physical destruction," Greenspan said in testimony to the Senate Banking Committee.

In his speech, Bush will make the case against No. 1 suspect bin Laden and his al-Qaida network, officials said.

With the speech in the Capitol taking place under exceptionally tight security, Fleischer said that Vice President Dick Cheney will not attend but will remain in a secret, secure location in recognition of "the continuation of important government issues" should terrorists strike again. British Prime Minister Tony Blair will attend.

In the Afghan capital of Kabul, Islamic clerics Thursday urged bin Laden to leave Afghanistan voluntarily, but set no deadline for him to decide, according to the news agency of the ruling Taliban militia.

The clerics said they are prepared to call for a holy war against the United States if U.S. troops attack Afghanistan in an attempt to capture him and members of his al-Qaida terrorist organization.

Conveying Bush's rejection, Fleischer said, "This is about much more than any one man being allowed to leave — presumably from one safe harbor to another safe harbor, if what he's doing is voluntary."

"The president has demanded that the key figures of the al-Qaida terrorist organization, including Osama bin Laden, be turned over to responsible authorities and that the Taliban close terrorist camps in Afghanistan. The United States stands behind those demands," Fleischer said.

Previewing the speech to Congress, the second of Bush's presidency, Fleischer said Bush would say the nation is engaged in a "battle between freedom and fear and freedom will prevail." The speech will last at least 30 minutes, he said.