"As well as things have gone, it's still a military mission and therefore lives are still at stake," said the aide, who requested anonymity. "But obviously the progress has been very good."

Jubilant crowds cheered US troops sweeping through Baghdad Wednesday as the Iraqi capital looked set to fall after three weeks of a US-led campaign aimed at ending Saddam's brutal rule.

"The president continues to get good reports from the field from a military point of view. He continues to be heartened with the progress we're making," the US official told reporters.

The Bush aide cautioned neighboring nations against admitting Saddam, saying any effort by the Iraqi dictator to seek refuge would be a "no go" from Washington's point of view.

"He had his opportunity to leave the country, and he didn't take it," said the official, referring to Bush's pre-war ultimatum giving Saddam 48 hours to avert military action by fleeing the country

Asked whether US forces would aim to stem looting in Iraqi cities, the official replied: "As the mission continues, security will improve and increase."

SPACE.WIRE