Speaking Tuesday at Fort Lewis, Defense Secretary Robert Gates said U.S. troops are well on their way toward handing over security responsibility to Iraqi forces, but he declined to set a timetable for how long that process will take.

Gates toured McChord Air Force Base and Fort Lewis on Monday and Tuesday, his first visit to the local installations since he became secretary in late 2006.

Speaking to reporters after a briefing with Stryker brigade soldiers, Gates said the U.S. mission began changing in Iraq after the withdrawal of the first surge brigade last December.

“I think this transition of control and responsibility ... for security is a process that is already well under way, and based on everything that I’m hearing, we’ll be able to continue,” Gates said.

“However long that takes really will depend on the situation on the ground, but things are going very well at this point.”

He declined to comment specifically on Iraqi Prime Minister Nouri al-Maliki’s call for a timetable for the withdrawal of foreign troops from his country.

Gates likewise did not offer on a question about whether he could live with a short-term agreement to keep U.S. forces there past the end of this year, rather than pressing ahead with what have apparently become contentious talks with Iraqi leaders over a long-term pact covering the presence and status of U.S. troops.

“Ambassador Crocker is in charge of those negotiations,” Gates said, referring to Ryan Crocker, U.S. ambassador to Iraq, “and I am principally concerned with having an agreement that will allow our forces to continue to do their job and to support the Iraqi government.”

Otherwise, Gates said he spent the majority of his time at the two installations speaking with service members and their family members, getting his picture taken with newborn babies at Madigan Army Medical Center, and lunching with McChord airmen.

It was the first local visit by a defense secretary since Donald Rumsfeld came to Fort Lewis in April 2002.

Gates and his wife Becky own a home at Big Lake near Mount Vernon, where they spent the Independence Day weekend. His aides said he scheduled the McChord and Lewis visits on his way back to the Pentagon.

“It’s been very useful,” Gates said of his visit. “The conversations with (noncommissioned officers) and their wives are always instructive for me, and I’m always impressed with their dedication and commitment.”

Tuesday morning he and his senior military adviser, Lt. Gen. Peter Chiarelli, who is soon to become vice chief of staff of the Army, talked with crews from four different Stryker variants from the 5th Brigade, 2nd Infantry Division.

Sgt. Eric Shuty showed him the latest version of the eight-wheeled armored truck, the Mobile Gun System, fitted with a 105mm gun.

Shuty is just back from Iraq where he served nearly 15 months with the first crews to use the MGS in combat, in B Company of the 2nd Battalion, 23rd Infantry Regiment.

“There are only so many people who have real, functional downrange experience with the truck,” Shuty said. “And as one of them, I was glad to come out here and tell him it’s a good vehicle. Buy more.”