Petraeus, regarded as the architect of the strategy, spoke to NATO TV as he prepared to leave Afghanistan to take up his new job as director of the U.S. Central Intelligence Agency.
"What we have done is implement the so-called NATO comprehensive approach, a civil-military campaign ... that does indeed embody many of the principles of the counterinsurgency field manual that we developed back in 2006, and which we employed in Iraq in the surge of 2007-2008," the general said.
"I think generally, it has borne fruit."
Petraeus, who headed U.S. Central Command before being appointed commander in Afghanistan, said there had been setbacks as well as successes in Afghanistan.
However, in the past year the coalition and Afghan forces have halted the Taliban's momentum in much of the country, and reversed the insurgent hold in central Helmand province, districts around Kandahar city and in and around the Afghan capital of Kabul, he said.
He also warned there is still a tough fight for control of the country.
The general also said enemy activity in the border area with Pakistan is a serious challenge. He said the International Security Assistance Force and Afghan forces have worked to establish a layered border defense in key locations such as between Khost province in Afghanistan and North Waziristan in Pakistan.
Petraeus said the Afghan regular army forces are "generally doing well."
Petraeus will hand over commander next week to Marine Corps Lt. Gen. John Allen, who has been nominated for promotion to general.