"Saddam Hussein is losing control of his country," President Bush said Sunday.
Bush attended church at Camp David, Md., with his wife, Laura, where he prayed for those killed.
"I pray for God's comfort and God's healing powers, to anybody, coalition force, American, Brit, anybody who loses a life in this, in our efforts to make the world more peaceful and more free," Bush told reporters.
Even as American forces suffered casualties and Iraq took POWs, Bush said he was pleased with the progress of the war.
"Saddam Hussein is losing control of his country," Bush said. He did not say whether he thought the Iraqi president was dead, alive or injured; a senior White House official said there was no new information about Hussein's status.
"It's going to take a while to achieve our objective, but we're on course, we're determined, and we're making good progress," said Bush, who aides said planned a midweek visit to a military base in the United States.
Bush spoke to reporters after an Arab satellite station aired footage from Iraqi television of interviews with what the station identified as captured American prisoners. The tape also showed bodies in uniform in an Iraqi morgue who the station said were Americans.
Bush, returning to the White House from Camp David, said he did not have all the details of what he called a potential capture but added: "We expect them to be treated humanely, just like we'll treat any prisoners of theirs that we capture humanely. If not, the people who mistreat the prisoners will be treated as war criminals."
Bush said he was being updated constantly about the war effort. He spent the afternoon in the White House residence meeting with advisers after an intelligence briefing early Sunday conducted by White House chief of staff Andrew Card and national security adviser Condoleezza Rice.
Participating in the briefing by videoconference were Marine Gen. Pete Pace, vice chairman of the Joint Chiefs of Staff; Defense Secretary Donald Rumsfeld; Deputy Defense Secretary Paul Wolfowitz and CIA director George Tenet.
The president sought to brace the country for what could be protracted military action. "This is just the beginning of a tough fight," he said. "We're slowly but surely achieving our objective. We're just in the beginning phases. We're executing a plan which will make it easier to achieve our objective and at the same time spare innocent life."
Asked whether there was a possibility of an Iraqi surrender, he said: "All I know is we got a game plan, a strategy, to free the Iraqi people from Saddam Hussein and rid his country of weapons of mass destruction. And we're on plan."
The president suggested it was too late for the Iraqi leader to give up power and halt war -- the condition Bush set last week for Iraq to avoid war. "He had his chance to go into exile."
But Bush promised that "massive amounts" of humanitarian aid were poised to move into Iraq in the next 36 hours.