US steps on the gas as Saddam refuses to bow

British and US aircraft showered parts of southeastern Iraq with nearly 2 million leaflets, urging Iraqi soldiers to refrain from using weapons of mass destruction or torching oil wells and advising them to lay down their weapons rather than die for a lost cause.

Caught in a sandstorm swirling across northern Kuwaiti desert, thousands of US Marines were taking up battle positions while messages were broadcast from US ships and aircraft telling Iraqi troops how to surrender.

Elsewhere in the desert, US forces donned the chemical weapons protection suits they would wear as they cross into southern Iraq. Kuwaiti security sources said troops were moving into the demilitarised zone that straddles the Iraq-Kuwait border.

‘‘Troops walked into the DMZ this morning at around 11 am (0800 GMT),’’ a Kuwaiti security force source working in the Umm Qasr area in the east of the zone said. ‘‘American convoys are still driving towards Umm Qasr.’’

Iraqi officials warned Bush he was sending his troops to certain death as legislators meeting at an emergency session of Parliament pledged to shed their blood to defend the man who has led them since 1979.

‘‘History will recall how the people of Iraq, under the glorious leadership of Saddam Hussein, inflicted a lesson on the worthless,’’ the parliamentarians said in a unanimous declaration rejecting the US war ultimatum. ‘‘We will all be martyrs defending Iraq,’’ they said in a letter to Saddam.

Iraq’s information Minister, Mohammed Saeed al-Sahaf, said in Baghdad an invasion of Iraq would fail. ‘‘What they are facing is definite death,’’ he said of US and British soldiers.

President George W Bush and British Prime Minister Tony Blair have massed 280,000 troops in the region to kill or capture Saddam and overthrow his government in an enterprise that has created deep diplomatic schisms across the world.

Bush, accusing Saddam of hiding chemical and biological weapons, has given him until 4 am Iraqi time (0100 GMT) on Thursday to go into exile with his sons.

Saddam, whose regime has been under crippling UN sanctions since it invaded Kuwait in August 1990, has repeatedly said Iraq no longer has any weapons of mass destruction.

The White House said US-led troops would enter Iraq to hunt for weapons even if Saddam went into exile with sons Uday and Qussay. If he stayed: ‘‘It would be Saddam Hussein’s final mistake,’’ said spokesman Ari Fleischer.

Lawmakers said Bush was expected to ask Congress for 100 billion dollars to pay for the invasion, which comes 12 years after Bush’s father and former president sent in a US-led coalition to oust Iraqi troops from Kuwait.

In a late boost for Washington, Turkey will put a motion to parliament on Wednesday allowing it to use its airspace. If approved, this could help US forces open a northern front.

US officials promise an aerial bombardment of such precision and intensity that it would isolate Saddam and his leadership and stun the Iraqi army into submission.

They say upward of 3,000 satellite-guided bombs and cruise missiles will be unleashed from sea and air on targets vital to Saddam’s government in a ‘‘shock and awe’’ start to the war.

Ground forces are expected to move in during or after a short, intense aerial bombardment to secure Iraq’s oil fields. Saddam loyalists torched wells in Kuwait in the 1991 Gulf War.

Vowing regime change, Bush says Iraq could provide groups like Al Qaeda with weapons that would exceed the bloodshed caused by the September 11, 2001 attacks on US cities.

The impending showdown has caused deep fractures in the international community, with nations such as Russia, China and France calling for more diplomacy to rid Iraq of its alleged arsenal of biological and chemical weapons.

France, Russia and Germany are expected to use a Wednesday UN meeting with Chief arms inspector Hans Blix as a forum to denounce the war. Blix’s inspectors have pulled out of Iraq.

Bush and Blair face opposition to war at home. The British leader won parliamentary backing on Tuesday for war, but suffered the biggest party revolt in living memory.

Washington said about 45 countries — privately or publicly — supported its intention to oust Saddam by force. The United States, Britain and Australia alone are providing combat troops.

South Korea, locked in a standoff with North Korea over the communist state’s nuclear ambitions, said on Wednesday it backed the US On Iraq and said it might contribute non-combat troops.

As the clock ticked, Bahraini King Hamad bin Isa al-Khalifa said his country was ready to offer sanctuary to Iraqi President Saddam Hussein to avert a US-led war, Bahrain’s official BNA news agency reported.

‘‘The Bahraini ruler said Bahrain…is ready to host IraqiPresident Saddam Hussein if he wants to reside there with all dignity,’’ BNA said.

Saudi Arabia threw its weight behind the idea of exile for the Iraqi leader and his family for the first time to avert a war. It did not offer to take him itself.

Egypt, an opponent of a war, accused Iraq of putting a volatile region in danger.

‘‘We are facing today exceptional circumstances which put on our shoulders major responsibilities to save the security and stability of the Arab region,’’ President Hosni Mubarak told Egyptians in a televised address.

The UN aid official in charge of Iraq, Ramiro Lopez da Silva, said war would trigger a major humanitarian disaster in a country already crippled by more than a decade of sanctions.

At nine possible targets around Baghdad, the sober truth was beginning to sink in for around 100 Western human shields.

‘‘I will stay till the bombs come down,’’ Briton Uzma Bashir said at a power plant on the city’s southern outskirts, admitting to a feeling of nervousness.