NATO chief Anders Fogh Rasmussen has said that he believes Afghan forces are capable of securing their own country by the end of 2014.
Mr Rasmussen told a press conference in Zagreb that "from 2015 we will continue in a supportive mission with a training mission. So we are on the right track.
A day earlier, speaking in Slovenia, Rasmussen called the transition in Afghanistan "a logistical challenge".
The NATO-led International Security Assistance Force is to hand over security to local forces by the end of 2014.
From January 2015 onwards, NATO will remain in Afghanistan mainly for training, mentoring and assisting the Afghan forces.