MUNICH (Reuters) - The president of Afghanistan said on Sunday he would announce the start of a process to transfer 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 transition 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.