WASHINGTON - U.S. President Barack Obama has welcomed the security transition that took place in Afghanistan earlier in the day, saying world leaders will demonstrate their support for Afghanistan beyond 2014 in the upcoming NATO summit in Chicago.

The White House put out a statement on Sunday evening saying Obama welcomes Afghan President Hamid Karzai's announcement earlier in the day of the third tranche of areas to transition to Afghan security lead, saying the step is "an important step forward in our effort to achieve our objectives in Afghanistan."
The president's statement came as top Afghan peace negotiator Arsala Rahmani, a close adviser to Karzai, was gunned down in Kabul, and a day after two British NATO troops were killed by men in Afghan police uniforms.
Obama said as transition proceeds in these areas, nearly 75 percent of the population of Afghanistan will be living in provinces, districts and villages where Afghan forces are leading, while the Afghan National Security Forces are strengthening their capacity as the U.S. and its NATO allies are on track to transfer full security responsibility to the Afghan side by the end of 2014.
Referring to next week's NATO summit in Chicago, Obama said leaders will 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." He said he looks forward to meeting with Karzai in Chicago to "discuss these critical steps that will strengthen Afghan sovereignty while responsibly winding down the war."
An Afghan presidential spokesman on Sunday said the government of Afghanistan would soon begin the third phase of security transition from NATO-led troops to the national security force, with the Afghan side taking full control of Uruzgan, Kapisa and Parwan provinces and 122 districts throughout the country.
Meanwhile, U.S. Defense Secretary Leon Panetta also hailed the beginning of a new phase of security transition in Afghanistan.
Government officials said the handover's third phase would start immediately and could take as little as six months, although according to NATO's International Security Assistance Force, complete transition in an area can take 12-18 months.
NATO has a total of 130,000 soldiers helping the Karzai government fight an insurgency by hardline Taliban militants, and they are due to withdraw by the end of 2014 when the transition process is complete.