* U.S. eyeing tighter control of its Afghan contracts
* Timing of "endgame" depends on situation on ground
* Afghan mission "sustainable" despite some withdrawals (Adds comments by Gates, paragraphs 17-19)
By Phil Stewart
HALIFAX, Nova Scotia, Nov 20 (Reuters) - The United States must tighten control of Afghan aid contracts as a first step toward stemming rampant corruption, Defense Secretary Robert Gates said on Friday.
A central question as President Barack Obama debates sending up to 40,000 more troops to Afghanistan is whether the Afghan government can become a more credible partner in the war by tackling corruption undermining its legitimacy.
"The reality is that the international presence in Afghanistan has provided a significant influx of assistance dollars in contracts," Gates said.
"I think the place to start is the place we have the greatest leverage and that’s where we’re writing the checks," he told reporters during a trip to Canada.
Sworn in on Thursday for a second term after a fraud-scarred election, Afghan President Hamid Karzai promised both to fight corruption and to take control of security within five years, a key benchmark for an eventual drawdown on Western forces.
But U.S. officials have called for concrete action by Karzai to curb corruption, crucial to convince skeptics at home and abroad.
U.S. House of Representatives Speaker Nancy Pelosi on Friday called Karzai an "unworthy partner" who did not deserve a big boost either in U.S. troops or civilian aid. She said there was not strong support among her fellow Democrats in Congress for "any big ramp-up of troops."
Obama has said he hopes to wrap up the Afghan military mission before handing off to the next president — a window of between three and seven years, depending on whether he wins a second term in 2012.
Gates has said an eventual drawdown in Afghanistan could follow the Iraq model and go region by region. But he did not venture a guess about the timing of the U.S. military’s exit on Friday, saying: "The exact timing on that will depend clearly in substantial measure on the conditions on the ground."
Even after the military exit, the United States and other allies would continue to have a strong civilian presence in Afghanistan to "develop governance and their economy over the long term," he said.
"We are not going to do what we did in 1989 and turn our backs on Afghanistan," Gates said.
Gates spoke after meeting Canada’s Defense Minister Peter MacKay, who restated Canada’s plans to withdraw its 2,800 soldiers now southern Afghanistan in 2011. Canadian Prime Minister Stephen Harper says he has no plans to ask for another extension.
The Netherlands is set to withdraw its forces in 2010.
Gates said the top U.S. and NATO commander in Afghanistan, General Stanley McChrystal, had factored the withdrawals into account during his war planning. But Gates also said he expected both countries to depart as close to their deadlines as possible.
"I think it is sustainable ... We know that this is coming, for the Dutch in 2010 and for Canada in 2011. And General McChrystal is planning appropriately," he said.
"Our expectation is that both countries will run through the tape ... for staying in the fight until the deadlines that they have come upon us," he said.
Speaking later at a security conference, Gates praised Canada’s military, which he said had "distinguished itself in battle in some of the most dangerous parts of the country."
"With more than 130 fallen heroes — among the highest of coalition members on a per capita basis — the Canadian army has certainly paid the price and borne the burden in Afghanistan," Gates said.
"We call on our other allies and friends to do what they can on behalf of this noble and necessary campaign — an effort that will ... require more commitment, more sacrifice, and more patience from the community of free nations." (Editing by Philip Barbara)