Hours before the deadline set by President Bush, Saddam Hussein gave no sign of yielding, and long columns of U.S. armored vehicles moved through swirling Kuwaiti sandstorms Wednesday toward Iraq's border.

In Baghdad, fortified by trenches and sandbags, streets were quieter than usual, with light traffic and some shops shuttered. Saddam ordered residents to stack wood and oil barrels to be set afire in hopes of concealing targets from bombardment.

Iraq's rubber-stamp parliament, at a special session, rejected the U.S. ultimatum and reaffirmed support for Saddam. The idea that he would flee into exile ''is absolutely unthinkable,'' said Speaker Saadoon Hammadi.

Just across Iraq's southern border, U.S. and British troops piled ammunition and combat gear into fighting vehicles and broke camp, ready to invade on short notice. One major deployment involved the U.S. Army's 3rd Infantry Division - its 20,000 soldiers and thousands of vehicles were ordered to positions close to the border.

In all, about 300,000 troops were within striking distance of Iraq, backed by more than 1,000 warplanes.

''We are one day closer to making history,'' Col. Michael Linnington, commander of the 101st Airborne Division's 3rd Brigade, told his officers at a briefing Wednesday morning.

The deadline set by Bush for Saddam to go into exile was 8 p.m. EST, which would be 4 a.m. Thursday in Baghdad.

At a news conference, Iraqi Information Minister Mohammed Saeed al-Sahhaf accused U.S. officials of lying to their troops about the losses they would suffer. The notion that invading Iraq ''will be like a picnic'' is ''a stupid idea,'' he said.

Though U.S. defense officials hope for a quick victory, with minimal casualties on both sides, they raised the possibility that Iraq would use chemical weapons. Pentagon officials said intelligence reports suggest Saddam has given field commanders authority to use such weapons.

The top American general in Kuwait, Lt. Gen. David D. McKiernan, warned against any such tactics. ''It would be a hugely bad choice on the part of any Iraqi leader or commander to employ chemical weapons,'' he said.

Chief U.N. weapons inspector Hans Blix said he does not believe Saddam's government would use chemical or biological weapons even as a last resort because it would turn world opinion in favor of the United States. ''Some people care about their reputation even after death,'' Blix said.

Confident that Saddam will be overthrown swiftly, the United States and Britain are working on a plan to use Iraqi oil proceeds from a $40 billion U.N.-controlled account to pay for humanitarian relief during a war.