The expansion of NATO's UN-mandated International Security Assistance Force (ISAF) into southern Afghanistan will take the size of the force to about 18,000 troops.
It will also boost the number of troops in the six southern provinces to 8,000, more than double the figure at the end of last year.
ISAF was formed to assist the Afghan government secure the country soon after the Taliban was toppled in 2001. The force came under NATO command in 2003, becoming its first mission outside of the Europe Atlantic area.
ISAF, which includes troops from 36 countries, has been operating in northern and western Afghanistan and the capital Kabul.
After the expansion southwards, it is due to move into the east of the country later this year eventually reaching about 23,000.
Here are rough breakdowns of the soldiers that will fall under ISAF after the transfer of command in the south, expected July 31.
Main deployments to ISAF in the south
Britain 4,000 (when all troops in place)
Canada 2,300
Netherlands 1,400 (when all troops in place)
There will also be troops from the United States, which will also maintain a counterinsurgency force.
Main deployments elsewhere in the country
Germany 2,900
Italy 1,200
Britain 1,100
France 900
Spain 600
The countries supporting the ISAF mission are: Albania, Austria, Azerbaijan, Belgium, Britain, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, Finland, France, former Yugoslav republic of Macedonia, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United States.
Role: ISAF's primary role is to support the Afghan government in providing and maintaining a secure environment in order to facilitate the re-building of Afghanistan. ISAF also has responsibility for a number of provincial reconstruction teams, civilians and military teams that facilitate development.
