BAGHDAD — U.S. Defense Secretary Robert Gates arrived in Baghdad for meetings today with Iraq's political leaders, including Prime Minister Nouri al-Maliki, as well as Gen. Ray Odierno, the top U.S. commander there.

Gates flew to the capital after a stop in southern Iraq, where he got a firsthand look Tuesday at the future of the U.S. military mission.

The secretary began his Iraq trip with a visit to a command post in Talil, where U.S. troops are serving mainly as advisers to Iraqi forces. The advisory unit in Talil is a prototype for U.S. forces as they shift from front-line combat to support roles.

Gates met with U.S. and Iraqi officers who have patroling together since July 15. And he saw the command center, a room where U.S. and Iraqi commanders meet each morning to go over coordination of patrols.

"What you are doing here is the next phase of our progress in Iraq," Gates told U.S. troops.

He told reporters he was impressed by an artillery brigade that had come to Iraq in spring thinking it would be on the front lines but quickly adapted to its advisory role. "This is a symbol of how flexible our forces are," he said.

Gates described the ground-level relationship with Iraq: "Nobody's the boss or the occupier."

He also got a briefing from the No. 2 U.S. commander in Iraq, Lt. Gen. Charles Jacoby, who said overall coordination is going very well since the U.S. handed over control of the cities to Iraqi forces on June 30. Jacoby said coordination has gone particularly smoothly in Baghdad.

Gates is also expected to visit Iraq's restive Kurdish region, where challengers made a surprisingly strong showing in regional elections over the weekend.

Kurds were united in their hard line in disputes with Iraq's Arabs over oil-rich territory, which threaten to erupt into new violence even as the U.S. military prepares to withdraw its forces by the end of 2011.