"Our combat troops will begin leaving Afghanistan soil in the next few weeks," Hollande said, adding that the withdrawal would take place "in order and security".
Before his election in May, Hollande promised to speed up France's withdrawal from Afghanistan so it would be completed by the end of 2012 – a year earlier than Paris initially planned and two years before a NATO deadline.
In a ceremony also attended by former president Nicolas Sarkozy, the four soldiers were given a military funeral in the courtyard of the Les Invalides military monument.
The four French soldiers were killed on Saturday in an attack by a Taliban suicide bomber in Kapisa province in eastern Afghanistan and were France's first casualties in Afghanistan since Hollande took office.
A total of 87 French soldiers have died in Afghanistan since the start of NATO-led operations against the Taliban in the country in 2001, including nine since the start of 2012.