Unofficial discussions have been held with Taliban representatives over an extended period, Karzai told CNN's "Larry King Live" in an interview to be broadcast Monday.
"We have been talking to the Taliban as countryman to countryman," said Karzai. "Not as a regular official contact with the Taliban with a fixed address, but rather unofficial personal contacts have been going on for quite some time."
Afghan presidential spokesman Waheed Omar has said previously that the administration was in contact "for the past couple of years" with "different levels of Afghan Taliban wanting to reconnect with the government." It was not immediately clear if the Karzai interview was the first time the president acknowledged the talks directly.
NATO's top commander in Afghanistan - Gen. David Petraeus - has also said themade by Taliban insurgents at the highest levels to the Afghan government.
The drumbeat about talks comes as support for a drawn-out military push in Afghanistan is waning in the U.S. and with other NATO allies as the war enters its 10th year. Sending thousands more U.S. troops this summer to the country's south has yet to show significantly increased security in the Taliban heartland.
The violence, meanwhile,. Roadside bombs killed eleven people including two NATO troops, and a suicide bomber blew up his vehicle near a military convoy, killing a child and wounding two others.
The Afghan government says it hopes to make talks more structured with a "peace council" that will aim for formal talks with insurgent groups. On Sunday, former President Burhanuddin Rabbani was named chief of the council. Karzai praised the choice by the 70-member group, saying Rabbani's leadership would be "good for Afghanistan."
Rabbani was one of a group of mujahedeen leaders who fought the Soviets in the 1980s. He was Afghanistan's president between 1992 and 1996, when he was ousted by the Taliban.
"How much longer can we wait for foreigners to establish security for us? How much longer can we witness explosions in our mosques and see our leaders killed?" Rabbani said as he accepted the position. "Peace will come when we cooperate." The panel formally began work on Thursday.
Publicly, the Taliban have said they won't negotiate until foreign troops leave the country, yet many Taliban leaders have reached out directly or indirectly to the highest levels of the Afghan government.
There have been no formal negotiations yet between the Afghan government and the Taliban, only some contacts and signals from each side, according to Karzai's spokesman, Omar.
Last February, Karzai sent a small delegation of former Taliban members to Saudi Arabia to seek the kingdom's help in kick-starting talks with the Taliban. But Saudi Foreign Minister Prince Saud al-Faisal said the kingdom would not get involved in peacemaking unless the Taliban severed all ties with bin Laden and his al Qaeda terror network - a key U.S. demand.
One of the former Taliban members, Abdul Salam Zaeef, said unequivocally then that he could not negotiate on behalf of the Taliban. The meeting ended without any results.