FROM STAFF REPORTS
SOUTH-CENTRAL IRAQ - The U.S. Army's 3rd Infantry Division, 7th Cavalry Regiment, crossed the Euphrates River early Tuesday, establishing a line of coalition forces from the southern Iraqi city of Basra north toward Baghdad.
The movement of the 3rd Infantry Division, along with the northward movement of the Marines' First Expeditionary Force towards Al-Kut, sets up a pending showdown between U.S. ground forces and Iraq's Republican Guard, their most highly-trained soldiers.
U.S. and British forces are positioned in a column, from Umm Qasr up the Euphrates to just south of Karbala, approximately 60 miles south of Baghdad.
A confrontation also looms in Basra, which allied forces had hoped to take without a fight, according to British military officials.
Resistance from the Saddam Fedayeen - militia members loyal to the Iraq's embattled leader - as well as the recent repositioning of Iraqi Army Divisions inside Basra have prompted coalition forces to plan for a military operation for the city.
Coalition troops had hoped to isolate the city and any Iraqi forces in it, while the main ground force surged north toward Baghdad.
The possibility of a humanitarian crisis inside Basra has added significance to the impending conflict. Most of Iraq's second largest city has been largely without electricity and water since last Friday. The Americans and British had planned to use Basra as a hub for humanitarian aid for Iraqi civilians.
British military officials said Tuesday that coalition forces have full control of Umm Qasr, the southern entry point for humanitarian aid.
British Prime Minister Tony Blair will come to the United States as early as Thursday to discuss war strategy with President Bush at Camp David, Maryland, government sources said.
Large explosions and anti-aircraft tracer fire continue to flash in the night sky over Baghdad. Earlier this week, coalition air forces struck an Iraqi air force complex and Saddam International Airport.
U.S. Intelligence reports have suggested Republican Guard units may have been ordered to use chemical weapons against U.S. forces if they cross a "red line" territory marker issued by Saddam.
According to information released by the U.S. Central Command in Qatar, coalition aircraft on the USS Theodore Roosevelt, located in the eastern Mediterranean Sea, are switching from bombing campaigns with set targets to missions where they are authorized to attack "targets of opportunity" and to supply air support to ground forces.
(Managing Editor's Note: Information from national media sources - both cnn.com and msnbc.com - was used in the compilation of this report)