KABUL (Agencies) — Afghan President Hamid Karzai, who for years pushed for reconciliation with the Taliban, now says attempts to negotiate with the insurgent movement are futile and efforts at dialogue should focus instead on neighboring Pakistan.

The Afghan leader explained in a videotaped speech released by his office Saturday that he changed his views after a suicide bomber, claiming to be a peace emissary from the insurgents, killed former Afghan President Burhanuddin Rabbani at his home on Sept. 20. Rabbani was leading Karzai's effort to broker peace with the Taliban, AP reported.

"Their messengers are coming and killing. ... So with whom should we make peace?" Karzai said in the recorded address Friday to a gathering of the nation's top religious leaders.

"I cannot find Mullah Mohammad Omar," Karzai said, referring to the Taliban's one-eyed leader. "Where is he? I cannot find the Taliban council. Where is it?

"I don't have any other answer except to say that the other side for this negotiation is Pakistan," Karzai said.

Most of the Taliban leadership is thought to be living in Pakistan, and its governing council — known as the Quetta Shura — is based in the southern Pakistani city of the same name. 

Afghanistan said Saturday it had evidence that Rabbani's assassination was planned by Taliban figures living in Quetta.

An Afghan government statement issued earlier in the past week said Pakistan had failed to take steps to eliminate terrorist sanctuaries. It added that if Pakistan's intelligence service is using the Taliban against Afghanistan, then the Afghan government needs to have negotiations with Pakistan, "not the Taliban."

That statement was released after Karzai met with senior government, religious, political and jihadi leaders to discuss the peace effort.

NATO-led forces have captured Haji Mali Khan, a senior commander for the Haqqani network in Afghanistan, during an operation in eastern Paktia province earlier in the week.

Khan is "the uncle of Siraj and Badruddin Haqqani ... one of the highest ranking members of the Haqqani network and a revered elder of the Haqqani clan," the NATO-led International Security Assistance Force (ISAF) said in a statement on Saturday.

The Haqqani network, which attacked the U.S. embassy in Kabul earlier this month, is based on the Afghan-Pakistan border.

Admiral Mike Mullen, the U.S. joint chiefs of staff, recently accused the group of being a "veritable arm" of  Pakistan's military intelligence agency- a charge that Islamabad denies.

NATO said Khan had managed bases and operations in both Afghanistan and Pakistan, and moved forces across the border for attacks, as well as transferring funds and sourcing supplies.

Khan was seized Tuesday during an operation in eastern Paktia province's Jani Khel district, which borders Pakistan, the alliance said.

It was the most significant capture of a Haqqani leader in Afghanistan, and could dent the group's ability to operate along the porous border with Pakistan's lawless tribal areas.

Shortly after NATO's announcement, Taliban spokesman Zabiullah Mujahid denied in a message to Afghan media that Khan had been arrested but provided no evidence that he was free.