He announced the drawdown during a surprise visit to meet troops in Sarobi district near Kabul on Tuesday.
Talking to journalist Sarkozy said it was necessary to end the war, adding that There was never a question of keeping troops in Afghanistan indefinitely.
France has around 4,000 troops deployed in the country, mostly in Sarobi, Kabul, and in northeastern Kapisa province.
“We will withdraw a quarter of our troops, that’s to say 1,000 men, by the end of 2012,” he said. Those remaining in Afghanistan will be concentrated in Kapisa, where they have been deployed since 2008.