The U.S. defense secretary arrived in Iraq Thursday, after visiting several other countries in the region. It is his third trip to Iraq since he took up his post four months ago.
His visit is intended to urge Iraqi leaders to press ahead with efforts to reconcile the country's bitterly divided Shiite and Sunni communities and to push through legislation on the sharing of oil revenues among Sunnis, Shiites and Kurds.
Gates told reporters Thursday that he knows it will be difficult, but they must make every effort to pass the legislation quickly.
"I am sympathetic with some of the challenges that they face, but by the same token, to pick up General Petraeus' theme, the clock is ticking."
On Thursday, Gates met top U.S. commanders at a military base near the western city of Fallujah, in the volatile al-Anbar province, and discussed the recent high-profile bomb attacks in Baghdad that have killed more than 200 people since Wednesday.
The top U.S. commander in Iraq, General David Petraeus, said the Wednesday bombings were a setback that came just as he thought the new Baghdad Security Plan was starting to take hold.
"A day like that can have a real psychological impact. And it came at a time where, frankly, Lieutenant General (Ray) Odierno and I, and a lot of the other leaders in Baghdad and throughout Iraq, have felt that we were getting a bit of traction. You know it's very, it's almost imperceptible at times, but that there was slow progress with the Baghdad security plan and in some other parts of the country as well."
U.S. military officials point to the overall decrease in sectarian executions as one sign of progress, but concede that high-profile bombings continue to pose a challenge.