Afghanistan has said its forces will take over security in areas including the Helmand capital from NATO this summer.
The announcement kick-starts the transition as foreign troops plan to exit the country by the end of 2014.
Afghanistan will notably take 'full security responsibility' for most of Kabul province, including the capital and Lashkar Gah, the capital of the restive southern province of Helmand.
It will also assume security responsibilities for Panjshir province, Bamiyan province, most of Herat city, Mazar-i-Sharif, the capital of Balkh province, and Mehtarlam, the capital of Laghman province, he said.
'Afghanistan does not want others to be responsible for its security and defence,' President Hamid Karzai told senior army and police officers.
'This year is a milestone in the process of government-building and peace. This is the year of taking on more responsibility,' he added, in a speech delivered on the second day of the Afghan new year.
'I once again urge the armed opposition to stop their attacks and killings and join the peace process, otherwise they will be responsible for the continued presence of foreigners (in Afghanistan).'
President Karzai's announcement comes after battle-weary countries contributing to the NATO-led force agreed last year to begin putting the battlefield under his control, moving Western troops to a support role.
But with a major insurgency still raging, led by the Taliban and other extremist outfits, doubts remain over how ready the national security forces really are.
Afghan military leaders complain of a lack of resources and some analysts cite corruption and low retention rates.
Most of the provinces and cities to be placed under Afghan security control this summer are well away from the most fierce fighting in the south, with Lashkar Gah the only part of southern Afghanistan on the list.
Security in Helmand has improved substantially since the United States deployed an extra 30,000 troops in Afghanistan last year, mostly in the south, but experts say it remains fragile.
The transition in Lashkar Gah is likely to be largely symbolic, with NATO troops expected to remain in the city in large numbers in support of the Afghan National Security Forces after the handover.
President Barack Obama has said he wants US troops to begin leaving Afghanistan in July, amid waning domestic support for the war.
Last year was the deadliest by far for international troops since the conflict began in 2001, with more than 700 fatalities reported.
Afghanistan's security forces comprise 118,000 police officers and a 159,500-strong military.
