Afghan President Hamid Karzai said Tuesday it will be at least 15 years before his government can bankroll a security force strong enough to protect the country from the threat of insurgency.

Speaking at a news conference with U.S. Defense Secretary Robert Gates, Karzai said Afghan security forces would take the lead in securing the nation within five years, but he said his nation would need financial help to pay the salaries and equip a growing army and police force.

"Afghanistan is looking forward to taking on our responsibilities in terms of paying for its forces with its own resources, but that will not be for another 15 years," Karzai said.

Gates is the first member of President Barack Obama's Cabinet to visit since Obama announced last week that he is sending 30,000 reinforcements to Afghanistan, but intends to pare down the U.S. role in July 2011. He worked to convey two messages: that the U.S. would not abandon Afghanistan, as Gates said it did after the Soviets withdrew in 1989, but that the American commitment was not open-ended.

The defense secretary and other administration officials have described the 2011 date as just the beginning, with the process likely take at least two or three years to complete.

"There is a realism on our part that it will be some time" before the Afghan security forces can stand on their own, Gates said.

"Our troops are here only as long as it takes to help you defeat your enemies," he said. "We will fight by your side until Afghan forces are large enough and strong enough to secure the nation on their own as they have already done in Kabul."