( CNN ) -- Afghan President Hamid Karzai said Sunday that a critical phase in the transfer of security authority from international to domestic forces would begin March 21 , a precursor to a planned full handover three years hence . Karzai made the announcement during a speech at the Munich Security Conference , an annual gathering of diplomatic and military leaders from Western and other nations . `` We are determined to demonstrate Afghan leadership and ownership of the transition process , '' he said . NATO Secretary-General Anders Fogh Rasmussen , in an interview conducted with conference organizers and posted on its website , explained this move next month marks the start of `` a gradual transition to lead Afghan responsibility -- province by province , district by district . '' Thus , Afghans may take over full control in some locales relatively soon , while the process may take much longer elsewhere . `` I 'm very optimistic about this timetable leading to Afghan ( security ) responsibility all over Afghanistan by May 2014 , '' said Rasmussen . `` But I have to add , that obviously this development will depend on conditions on the ground . '' During his speech , Karzai credited the influx of 70,000 international forces in 2010 for improving the situation and helping Afghan security forces . He frequently mentioned the fight against the al Qaeda terror group , but did not mention the Taliban -- which was ousted from power in 2001 , for harboring al Qaeda , and has been behind many attacks since . `` We have regained the initiative , '' Karzai said . `` Security in the country is better than it was a year before , and the year before that . '' In a letter to troops late last month , U.S. Gen. David Petraeus voiced a similar sentiment , saying the surge `` inflicted enormous losses '' on militants and weakened terror networks . It came at a steep price : Last year was the deadliest for coalition and U.S. troops in Afghanistan since the war began . There were 708 such troops killed , of which 498 were American service members . Petraeus , the top U.S. commander in Afghanistan , said insurgents were now on the defensive in Afghanistan , and pointed specifically to progress in Kabul , where one-fifth of the Afghan population lives . Still , he cautioned that past success does n't guarantee a smooth road ahead . `` In sum , 2010 was a year of significant , hard-fought accomplishments , '' Petraeus wrote . `` The year ahead is likely to be a tough one , too . '' President Barack Obama has promised to begin a gradual withdrawal of U.S. troops from Afghanistan starting in July , a pledge he reiterated during his recent State of the Union address . During the speech Sunday , Karzai also acknowledged issues of corruption in Afghanistan , focusing especially on contracts that fell outside the Kabul government 's control . The president outlined efforts to curb abuses , which is the past he said had `` undermined the capacity of the state rather than building it . '' `` With the U.S. and NATO , we 're overhauling the system to make contracting an instrument of good rather than bad governance , '' he said . By 2015 , Karzai predicted that Afghanistan will have `` binding agreements with the United States and long-term partnerships with NATO '' -- noting that the shift in security responsibility does not mean a clean break with international forces that have been engaged there for nearly a decade . As to NATO 's role , the current head of the military and political Western alliance said he expected that some of its troops may still be in Afghanistan even after 2014 . `` I ... foresee a continued international presence , beyond the date when our combat mission ends , with the aim to assist the Afghans , '' Rasmussen said . Karzai closed his speech Sunday by again thanking other nations for committing financial resources to Afghanistan , as well as the human sacrifice many have made . And he urged them to continue to help , claiming Afghan 's prosperity and security was vital to the interests of the region and the world . `` Some journey is left and that journey will not be easy , '' Karzai said . `` But it 's a journey worth taking . ''
Afghan President Hamid Karzai made announcement Sunday at a security conference . The U.S. military has been training and advising the Afghans since 2001. Karzai credits the surge of international forces with improving security on the ground . He also outlines steps aimed at preventing corruption in Afghanistan .