Islamabad, Pakistan (CNN) -- Afghan President Hamid Karzai asked a Taliban-linked cleric based in Pakistan Saturday to help mediate talks with the Afghan Taliban, the cleric told CNN.
Maulana Samiul Haq said he told Karzai he was prepared to help bring Taliban leaders to the table if the Afghan president and his government had specific offers and demands.
"What can I convey to the Taliban if their demands and offers for solutions are not clear?" Haq said.
"Unless there's a concrete process in place, then things can't move forward."
Karzai has not yet commented on the cleric's remarks.
Haq -- known as one of the spiritual leaders of the Taliban movement -- met with Karzai during the final day of the Afghan president's visit to Pakistan.
The religious leader and former Pakistani senator runs an Islamic seminary in northwest Pakistan that produced many of the Afghan Taliban's leaders during the Afghan jihad against the Soviet occupation in the 1980s.
Haq says he is in contact with senior leaders of the Taliban but he didn't say who.
He said the Taliban have two key demands -- the exit of all foreign troops from Afghanistan and the release of Afghan Taliban prisoners from detention centers in Guantanamo Bay and Bagram Air Base.
"Thousands of people have been killed in Afghanistan. Why should the Taliban start a dialogue without a guarantee that foreign forces will leave the region?" Haq said.
Haq said the Taliban are reluctant to negotiate with Karzai because they view him as a supporter of U.S. policy in the region.
"He needs to change that impression," Haq said.
Haq's comments come after the Taliban rejected a reported claim Thursday by Karzai that the movement was taking part in secret talks with the Afghan government.
The statement followed a report in the Wall Street Journal in which Karzai said, "There have been contacts between the U.S. government and the Taliban, there have been contacts between the Afghan government and the Taliban, and there have been some contacts that we have made, all of us together."
Karzai's assertion suggested a change in course for peace efforts, because the Taliban has long publicly refused to meet with Karzai's government, and Afghan officials have complained they were largely sidelined in talks taking place between the United States and the Taliban.
"The last cards are with us. So far, it has been a U.S.-Taliban business. We have not been involved in this so I cannot say what was discussed," an Afghan government official told CNN last month.
Last June, Karzai said the United States was involved in peace talks with the Taliban, and that representatives of the government and insurgents had been in touch, but that no high-level meetings had taken place.
Karzai arrived Thursday in Pakistan for discussions with President Asif Ali Zardari on improving relations between the two countries and peace efforts in Afghanistan.
Journalist Nasir Habib contributed to this report.