"NATO will take over everything involving organization, implementation, planning and command" of the ISAF mission, which has patrolled Kabul and its environs since its creation in December 2001 following the fall of the Taliban militia, said one diplomat.

ISAF currently comprises some 4,600 troops from 29 countries, including around 2,500 German military and 600 Dutch soldiers, and provides assistance to Afghan authorities in securing Kabul.

Germany and the Netherlands took over joint control of ISAF from Turkey in February. Berlin has urged NATO to take over the leadership role at the end of the current mandate in August, but other countries including France and Belgium had expressed reservations.

Formally, ISAF will not become a NATO mission, the source said, addding that it would be a "successor mission". "Neither the name nor the mandate of this force will change," he said.

The exact date of handover remains to be decided, diplomats said.

The decision was taken by the Alliance's ruling North Atlantic Council (NAC) at the NATO's Brussels headquarters Wednesday morning, diplomats said, although no official announcement was made.

NATO is currently undergoing a radical transformation, from a Cold War-era bloc whose actions have been geographically limited to a post-September 11 force focussed on threats worldwide.

At a landmark summit in Prague last year it agreed to expand to take in seven ex-communist countries, while also approving the creation of a rapid Response Force (NRF) ready for combat missions anywhere around the globe.

Wednesday's decision is the first time since NATO's creation in 1949 that it has agreed to take command of a mission outside the north Atlantic area.

"This decision puts to rest the debate about NATO's relevance", said one diplomat.

NATO, which already provides logistical support to ISAF, asked its military experts on April 2 to study how the alliance could "maximize" the Alliance's role in Afghanistan.

NATO's top military commander in Europe, General James L. Jones, said last month that the alliance was ready to play a leading role, if called upon.

"I am quite sure that NATO assets could be used, and could be used effectively," he said after talks with German Defence Minister Peter Struck.

Security remains a major concern for the government of President Hamid Karzai as Afghanistan struggles to overcome decades of conflict and warlordism.

While ISAF is responsible for security in Kabul, an 11,500 strong US-led coalition force is hunting down Taliban and al-Qaeda remnants across the central Asian nation.

ISAF's compound in Kabul was hit in a rocket attack las month, while US Special Forces also came under attack in the neighbouring Kandahar province.

Kandahar is the heartland of the Taliban regime, which was toppled by a US-led coalition following the September 11, 2001 attacks on New York and Washington masterminded by al-Qaeda leader Osama bin Laden.

SPACE.WIRE