MUNICH (Reuters) - The president of Afghanistan said Sunday he would announce the start of a process to transfer the responsibility for security to Afghan forces from international forces on March 21.

NATO agreed with President Hamid Karzai at a summit in November to begin the handover to Afghan forces this year with the aim of completing the process by the end of 2014.

The Western military alliance has said it hopes to launch the process, which is aimed at a gradual reduction of the 150,000 foreign troops in the country, next month.

Karzai told an international security conference in Munich that the Afghan government was determined to show leadership, adding: "I will announce the first phase of transition on the Afghan New Year, which is the 21st of March."

Karzai said this had been made possible by a big effort to boost the size of the Afghan security forces.

NATO has stressed that transition will be a gradual process, district by district and province by province, and will depend on security conditions.

NATO initially planned to start the handover at the end of last year. But this was hampered by slow progress in building up Afghan forces and by an increase in insurgent violence, which hit its worst levels since the overthrow of the Taliban in 2001.

Doubts over the transition process were underscored on Thursday by a survey that showed Afghanistan's police force is only slightly more popular than the Taliban in the insurgent heartlands of the south.

Results of the U.N.-commissioned survey portrayed a police force widely viewed by Afghans as corrupt and showing favoritism toward people based on personal connections.

Around half of the 5,052 Afghans surveyed across all 34 provinces said they would report crime elsewhere.

The findings were a blow to Western efforts to extend the reach of the central government and its security forces to areas under the sway of a parallel Taliban authority, particularly in the south which has borne the brunt of NATO and U.S. military operations to drive back the Islamist insurgents.

In Munich, Karzai repeated complaints that what he calls "parallel structures" -- private foreign security firms protecting international interests and Provincial Reconstruction Teams run by foreign military contingents -- were hampering efforts to expand the influence of the Afghan government.

He also said international backers of Afghanistan must stick to promises to channel a greater percentage of financial assistance through the Afghan government.

(Editing by Mark Heinrich)

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