The list, in the form of a "deck of cards" with pictures of the wanted figures, was distributed to the thousands of U.S. troops in the field to help them find the senior members of the government. It also was being put on posters and handbills for the Iraqi public, Brig. Gen. Vincent Brooks said.
Brooks did not identify figures on the list, except to suggest they included Saddam and his minister of information, Mohammed Saeed al-Sahhaf, who boasted of battlefield successes right up to the time he disappeared Tuesday.
"There are jokers in this deck, there is no doubt about that," Brooks said.
He said the whereabouts of some of the most-wanted figures were unknown, while others might well be dead.
"The population will probably confirm that for us," he said.
"The key list has 55 individuals who may be pursued, killed or captured, and the list does not exclude leaders who may have already been killed or captured," Brooks said.
The U.S. forces have twice bombed sites where they believe Saddam may have been staying, and his fate is still unknown. One key figure who British and U.S. officials believe is dead is Ali Hassan al-Majid, a former Iraqi defense chief known as "Chemical Ali" for his role in the 1988 chemical weapons attacks on Iraqi Kurds.
Brooks also said that U.S. forces found and destroyed five small airplanes covered by camouflage netting along Highway 1 near the northern city of Tikrit, Saddam's birthplace.
The planes, he said, could have been used for escape or to distribute weapons of mass destruction. They were located after special forces north of Tikrit got caught up in a firefight with Iraqi troops, he said.
Brooks said there were increasing indications that regime leaders were trying to flee, including being smuggled out, flying out or driving out — and that serious firefights have erupted in areas where such convoys may have been moving.
He noted that special operations forces had taken the surrender of an Iraqi colonel responsible for Iraqi checkpoints leading into Syria along highways 10 and 11 in far western Iraq, and that coalition troops now controlled the crossings.
U.S. officials have said Iraqi regime officials have fled to Syria, and Brooks hinted Friday that they were going to other countries as well, although he didn't identify which ones.
Also in western Iraq, Brooks acknowledged particularly fierce defenses around al-Qa'im along the border with Syria, and said coalition forces believed it may be a site for weapons of mass destruction.
Previously, officials have noted that most Iraqi surface-to-surface missiles fired in the 1991 Gulf War were launched from the al-Qa'im area and that it was a possible crossroads into Syria for fleeing regime officials.
"The degree of defense there and intensity causes it to be of interest to us and it, obviously, is of interest to the regime," he said.