Although diplomats and officials say talks are at a very early stage, Karzai's remarks highlight the increasing focus on finding a political solution in Afghanistan as foreign combat troops prepare to pull out by 2014.
"Talks with the Taliban have started... the talks are going on well," Karzai said, addressing a conference in Kabul.
"Also foreign forces, especially the United States, are carrying out the talks themselves."
But the problems surrounding any reconciliation bid were thrown into sharp focus shortly afterwards when nine people died as three Taliban attackers armed with suicide vests and machine guns stormed a Kabul police station.
A British soldier was shot dead in an insurgent attack, the defence ministry said, while France confirmed one of its troops was also fatally wounded by militant gunfire.
The militants have consistently rejected any efforts to talk peace in public statements.
"We have already said this and have repeated it many times. We have no negotiation with the United States and we deny any report as such," Taliban spokesman Zabihullah Mujahid told AFP.
A report last month in Der Spiegel magazine claimed Germany was helping to mediate secret, direct talks between the US and the Taliban on German soil while the New Yorker magazine reported in February that the US had begun direct discussions with senior Taliban figures.
Karzai's comments came the day after the United Nations Security Council agreed to split the international sanctions regime for the Taliban and Al-Qaeda.
The move sends "a clear message to the Taliban that there is a future for those who separate from Al-Qaeda, renounce violence and abide by the Afghan constitution," said Susan Rice, UN envoy for the United States, which led the campaign for the division.
Afghan attempts to pursue talks with the Taliban have been public for months -- Karzai last year set up a High Council for Peace to look at the issue.
But efforts to negotiate hit an embarrassing set-back when reports in November said a Pakistani shopkeeper posing as a senior Taliban leader had been brought to Kabul for talks with the president before being exposed as a fake.
US President Barack Obama is expected to announce soon how many troops from his country will pull out from July as the process of handing control from foreign to Afghan forces starts.
It is due to conclude in 2014, when all foreign forces are scheduled to leave Afghanistan.