Updated

U.S. Defense Secretary Robert Gates said Monday he foresees a shrinking U.S. combat role in Iraq in coming months, while the No. 2 American commander here cautioned that it would be a mistake to push the U.S.-trained Iraqi army and police into a leading security role before they are ready.

"I'm not sure that pushing them forward is the right thing that we want to do. We tried that once before and found that that didn't work," Lt. Gen. Lloyd Austin told reporters, referring to the pre-2007 U.S. strategy, which focused on handing off security responsibility to the Iraqis as quickly as possible while reducing the U.S. presence.

That approach faltered, leaving Iraq on the brink of all-out civil war before U.S. President George W. Bush switched strategies and put Gen. David Petraeus in charge in Baghdad.

Austin said key measures of insurgent violence today are about 80 percent lower than one year ago.

Petraeus is scheduled to hand off on Tuesday to his successor, Lt. Gen. Ray Odierno. Odierno, who served for 15 months as the No. 2 U.S. commander here before leaving last February, will be promoted to four-star rank at a separate ceremony prior to the formal change-of-command ceremony.

Gates, who planned to preside at the change-of-command ceremony, told reporters traveling with him on an overnight flight from Washington that conditions have improved enough to permit a continuation of the process of handing off responsibility to the Iraqi security forces. Last week he told Congress that the war was now in the "endgame," with U.S. forces drawing back to a secondary role.

Although no additional U.S. combat brigades are to withdraw from Iraq this year, under a plan announced by Bush last week, Gates told reporters that he expects the U.S. combat role to keep shrinking.

"We are clearly in a mission transition," he said.

U.S. troops will increasingly play a backup role, Gates said, as Iraqi security forces take on more of the responsibility for fighting an insurgency that has lost much of its power and influence over the past year.

"The areas in which we are seriously engaged (in fighting) will, I think, continue to narrow," Gates said.

Austin's remarks in a separate interview with U.S. reporters on Monday in no way contradicted Gates. But the general put greater emphasis on caution, saying that although security is better, it remains fragile.

"You can rush to failure here if you're not careful," Austin said. "You really have to make sure that all the elements are in place to guarantee sustainable security — the army, the police, the border enforcement agencies."

The biggest uncertainty at the moment, Austin said, is the central government's inability thus far to pass the legislation needed to hold provincial elections across the country before the end of the year.

Gates was meeting with Iraqi Prime Minister Nouri al-Maliki later Monday. Before that he sat before an array of Iraqi military and local government leaders from the Rashid district of south Baghdad and heard assurances that they are cooperating to resettle citizens — both Shiites and Sunnis — who were displaced by the sectarian violence. They also pledged to work together on other thorny issues.

"I'm very encouraged by what I've heard," Gates said when they had finished.

In the interview, Gates said he is focusing heavily now on expanding the use and effectiveness of intelligence and surveillance programs that have played an important part in eroding the insurgency in Iraq.

Sandstorms prevented Gates' aircraft from stopping as planned at Camp Speicher, near the northern city of Tikrit, to receive a briefing on a once-secret program, known as Task Force Odin. The program has innovatively linked a variety of surveillance and reconnaissance aircraft — drones as well as manned planes — with new sensor technologies to hunt down insurgent cells. Those assets also are linked to attack helicopters and other planes capable of striking at discrete targets on short notice, day and night. One of the keys has been expanding the availability of full-motion video cameras aboard aircraft that can transmit live images to other aircraft and to ground stations, enabling quick action.

"We have a lot more plans under way" for expanding that program, Gates said.

He told Congress last week that he wants to replicate Task Force Odin in Afghanistan as soon as possible.

Lt. Gen. Richard Zahner, the deputy undersecretary of defense for intelligence, who was traveling with Gates, told reporters during a stop at Incirlik air base in Turkey on Monday that he is pushing a plan to expand the uses of similar intelligence and surveillance operations in both Iraq and Afghanistan.

Zahner said, for example, that the number of 24-hour-a-day "orbits" — nonstop air patrols over a particular area using remotely piloted Predators and other drones, teamed with specially equipped manned intelligence aircraft — in Iraq and Afghanistan combined has climbed from 12 in June 2007 to 27 today. It is due to rise to 28 next month and he hopes to push it to about 55 by the end of 2009.

Geoff Morrell, the press secretary to Gates, said Congress has been asked to provide $1.2 billion for the expansion of such programs in Afghanistan, where the insurgency has become more active and more deadly.