Kabul, Afghanistan (CNN) -- An Afghan official involved in setting up peace talks with the Taliban was gunned down in Kabul on Sunday as Afghanistan announced plans to take control of security over more of its territory.
Gunmen killed Moulavi Arsala Rahmani while he was on his way to work Sunday morning, the Afghan interior ministry said. Rahmani was a senator and Cabinet minister in the former Taliban government when the Islamic militia ruled most of the country, but in recent years had been a senior member of the High Peace Council.
Rahmani played a key role in efforts to bring Taliban leaders to the negotiation table. Authorities were searching for the attackers, the interior ministry said. Afghan President Hamid Karzai condemned the killing, praising Rahmani as a warrior-turned-politician "and a great pacifist."
"Enemies of Afghanistan must know that every Afghan wants peace and progress in their country and, thus Mawlavi Arsala was not alone in this journey," Karzai said in a statement.
The Taliban, which has been fighting government forces and U.S.-led NATO troops for more than a decade, announced recently that peace council members would be targets of its spring offensive. But Taliban spokesman Zabiullah Mujahid said in a text message Sunday that the group did not kill Rahmani.
He died the same day that Afghanistan released a new list of areas in which responsibility for security will be transferred from U.S. and allied troops to Afghan forces. Those include the city of Kandahar, the Taliban's historical seat of power and until recently one of its strongholds.
The rest of the list includes other volatile areas, including about half of the insurgent hotbed of Nurestan province, a third of violent Paktika province's districts and all of Uruzgan province, where departing Australian forces are active.
The plan means Afghan officials will have control over more than 75% of their own territory, Gen. John Allen, the commander of NATO's International Security Assistance Force, said Sunday. And NATO Secretary General Anders Fogh Rasmussen said once the move is implemented, "transition will have begun in every one of the 34 provinces of Afghanistan, including every provincial capital."
"This is thanks to the courage and determination of the Afghan people, the Afghan security forces and ISAF, and it is a result of the progress we have already made," Rasmussen said in a statement. "Together, we are moving steadily closer to our shared goal: to see the Afghan forces fully in charge of their country's security by the end of 2014."
In a statement from the White House, U.S. President Barack Obama said the news was "an important step" in the plan to have Afghanistan take full control of its security by the end of 2014, when NATO combat forces are scheduled to leave.
"A week from now, world leaders will gather at the NATO Summit in Chicago to discuss how we can effectively advance the transition process as our forces move from combat to a support role, and demonstrate our enduring support for the Afghan Government and Afghan National Security Forces," Obama said. "I look forward to meeting with President Karzai and my fellow leaders in Chicago to discuss these critical steps that will strengthen Afghan sovereignty while responsibly winding down the war."
But the ongoing conflict claimed the lives of two more NATO troops Sunday, bringing the allied toll to eight dead in three days. The latest were killed in a bombing in eastern Afghanistan, ISAF said.
Three others killed in the past few days are believed to be victims of so-called "green on blue" attacks, in which Afghan security forces turned their weapons on ISAF personnel. Two of those were British troops, the MInistry of Defense in London said.
"Serving as part of an advisory team, the two servicemen were providing security for a meeting with local officials near patrol base Attal, in the Lashkar Gah district of Helmand province, when they were shot and killed by members of the Afghan Police Force."
The remaining ISAF deaths include one service member killed in an insurgent attack, one killed by a roadside bomb and one who died of non-combat related injuries, officials said.
Gen. Mohamed Zahir Azimi, spokesman for the defense ministry, said Afghan officials hope to get commitments for support after 2014 from the leaders the Chicago summit. The country already has international commitments for $4.1 billion a year to fund the Afghan security forces until 2014, he said.
In Washington, U.S. Rep. Peter King, the Republican chairman of the House Homeland Security Committee, said Rahmani's death and the killings of allied forces illustrate "how difficult it still is in Afghanistan. And quite frankly, I think we should not be giving these target dates for getting out."
And Sen. Joe Lieberman, the independent chairman of the Senate Homeland Security Committee, said that while low-level Taliban leaders have given up the fight, "The people at the top of the Taliban, in my opinion, are not interested in reconciliation."
"This is the second murder of this kind of somebody high up in Afghanistan who turned and tried to be a peacemaker. So it's obvious they don't want peace right now," Lieberman said. Without ongoing U.S. pressure, he said, "They are never going to come to the table and have genuine peace negotiations."
CNN's Masoud Popalzai, Nick Paton Walsh, and Josh Levs contributed to this report.