BRUSSELS, Feb. 7 (Xinhua) -- NATO is expected to start the transition process in Afghanistan in the first half of this year, the alliance's chief said here on Monday.

NATO Secretary-general Anders Fogh Rasmussen told a press conference that Afghan President Hamid Karzai would unveil on March 21 the first provinces where Afghan forces would take over from NATO, but this is not the real start of the transition process.

"After that, a more practical implementation process will start. It's premature to say anything about when the physical transition will take place, but it will be in the first half of 2011, as I see it today," he told reporters.

At a summit in Lisbon in November, the alliance decided to start the transfer of responsibility for security to the Afghan army and police at the beginning of 2011 and complete it by 2014.

Fogh Rasmussen said he was optimistic about the timetable as the Afghan security forces have grown rapidly in the size and quality.

"We have seen an improvement of quality and we will see further improvements in the coming years," he said.