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A soon-to-begin U.S. troop withdrawal from Afghanistan should leave combat power intact as long as possible to press an anti-Taliban offensive, U.S. Defense Secretary Robert Gates said Sunday. He said support troops should go first.

On his final trip to assess a war in its 10th year, Gates told soldiers the endgame in Afghanistan is more likely to turn out well if the drawdown promised by President Barack Obama begins with an emphasis on removing noncombat forces rather than the infantry and others still trying to cement recent gains against a resilient Taliban.

"If it were up to me, I would leave the shooters for last," he said.

The final decision is Obama's. The commander in chief soon will receive from Gen. David Petraeus, the top U.S. and NATO commander in Afghanistan, a range of options on how to begin the withdrawal in July and how to pace it over perhaps 18 month to 24 months, Gates said at this dusty logistics base in Kandahar province.

Obama planned to gather his national security team Monday for his monthly meeting on Afghanistan and Pakistan.

Military commanders typically want to keep as much firepower at their disposal as they can, for as long as they can, to achieve their mission. In the case of Afghanistan, the White House wants to ensure that the president's oft-repeated promise to begin a withdrawal in July yields more than a token gesture. The war has grown increasingly unpopular in Congress.

Gates met with Petraeus shortly after he arrived in Kabul on Saturday. Both men will soon end their tenures. Gates retires on June 30. Petraeus has been nominated to be the next CIA director, replacing Leon Panetta, whom Obama has chosen to succeed Gates at the Pentagon.

Gates said the main purpose of his visit was to deliver his personal thanks to troops. At each encounter Sunday, as he mentioned his gratitude for their efforts and the sacrifices of their families, he choked up.

"You all will be in my thoughts and prayers every day for the rest of my life," he said in a shaky voice to a group of several hundred soldiers at Marines at Camp Dwyer, an outpost on a bleak patch of Helmand province.

Gates said Obama's Cabinet has yet to begin a formal discussion of how to proceed with the planned troop withdrawal.

It has not even been decided, he said, whether Obama will announce only the number of troops to go home in July or whether he also will set a departure timeline, over a longer period, for all 30,000 of the extra troops that he sent to Afghanistan in 2010.

Those 30,000, an increase opposed by many in Obama's own party, raised the total number of U.S. troops in Afghanistan to 100,000 and deepened the political stakes for him in advance of the 2012 election.

Gates left no doubt that he prefers the president set the full timeline for sending home all 30,000 troops. That would lessen the possibility that allies and the Afghans would interpret the initial July move as an abandonment of the war, Gates said.

"To make a decision on July in complete isolation from anything else has no strategic meaning," Gates said from inside a steamy hut on Dwyer that offered modest relief from a searing afternoon sun.

He said it would make sense to begin reductions with support forces like those who constructed the buildings for the influx of new U.S. troops last year, particularly at Dwyer and other places in the south.

"I'd try to maximize my combat capability as long as this process goes on," he said, referring to removal of the extra 30,000 "surge" forces.

"That's a no-brainer."

It is likely, however, that the forces going home this summer and beyond will be a mix of combat and support troops, he said.

Gates said it would be a mistake to assume that Osama bin Laden's death last month has changed the war's outlook so much that speedier troop reductions are merited.

His view appeared to be seconded by Lt. Col. Clay Padgett, commander of the 1st Battalion, 22nd Infantry Regiment, whose troops operate in the Kandahar City area, known as the birthplace of the Taliban movement.

Among Afghans in that area, the al-Qaida leader's death was "just noted," and little more, he said.

Padgett's brigade commander, Col. Jeffrey Martindale, cited his soldiers' progress against the Taliban in Kandahar province over the past year.

"They're weak," he said.

But they are trying to stage a comeback in some areas where they once dominated.

Marine Maj. Gen. John A. Toolan, Jr., commander of all U.S. and NATO forces in southwest Afghanistan, told reporters that a few Taliban commanders have slipped back into Sangin, a city in Helmand largely cleared of Taliban over the past year.

"Yes, there is an attempt to take Sangin back," he said.

Padgett said local governments in southern Afghanistan are weak because they lack the "connective tissue" between the police and local civilian authorities to ensure that basic services are provided and that ordinary Afghans see less reason to support or tolerate the Taliban.

He said it's unclear whether recent improvements in governance will carry over once U.S. troops hand off full responsibility to the Afghans. He predicted that the outcome could be known within six months.

"It's either going to stick or it's going to go backward," he said.