Hollande said France would pay a "national homage" to the men killed in a suicide bombing and that five wounded soldiers would be repatriated rapidly.
Defence Minister Jean-Yves Le Drian will head to Afghanistan on Sunday.
Hollande said the withdrawal of French troops from Afghanistan, one of his presidential campaign pledges, "will begin in the month of July, will be carried out and be completed at the end of 2012."
"In the meantime, everything must be done for our troops to meet their obligations but with the highest level of security and with the greatest vigilance for the lives of the soldiers.
"I am making this engagement here and I will be the guarantor for this operation," Hollande said in the central town of Tulle, where he was to attend a commemoration of the massacre of civilians by the Nazis on June 9, 1944.
He added that the attack "does not change anything, it neither accelerates nor delays" withdrawal plans.
While some have called for the pullout to be sped up, "it is not possible to go faster," he said.
Burqa clad suicide bombing
Four troops killed in a suicide bombing on Saturday were the first French soldiers to be lost in Afghanistan since January 20, when an Afghan soldier shot dead four unarmed soldiers and wounded 15 others.
According to the French defence ministry, the soldiers taking part in a "control operation" in the eastern province of Kapisa bordering Pakistan where insurgents are very active.
Afghan interior ministry spokesman Sediq Sediqqi told AFP the attacker was disguised as a woman wearing a burqa.
Three of the five wounded were in critical condition.
Some 3,500 French soldiers are deployed in Afghanistan, mainly in Kabul and in Kapisa, the fifth largest contingent in NATO's 130,000-strong US-led force.
Since January's attack, France has begun accelerating the withdrawal of its troops, and French soldiers have been given instructions to minimise their exposure.
Allies have downplayed the impact of their early departure, saying Afghan troops are ready to take over.
While former right-wing French president Nicolas Sarkozy had set a deadline of end-2013 to bring home combat troops, Hollande, who defeated Sarkozy in a May election, has decided to bring the timetable forward.
France returns to the polls on Sunday in the first round of legislative elections in which Hollande's Socialists and their allies are hoping to win control of the National Assembly from the conservatives.
Pullout poses bigger headaches
Although Hollande's decision met with little resistance from NATO partners during a summit in Chicago, the actual pullout remains a complex process.
It would involve bringing 2,000 combat troops home within six months, with the remaining personnel to stay behind to take charge of repatriating military equipment including 900 armoured vehicles and over 1,000 containers.
Francois Heisbourg from the International Institute for Strategic Studies noted that the withdrawal of Soviet troops in Afghanistan in the 1990s took place with little losses but warned that insurgents' actions are unpredictable.
"Normally, it is not in the interest of the insurgents to delay the withdrawal, but they are divided among themselves and some could try to outdo the others," he said.
The relatively quiet Kabul district of Surobi, where French troops are also based, was handed over to local control in April.
Kapisa has been included in the third of a five-phase transfer, which Afghan officials say could take as little as six months, but which NATO's International Security Assistance Force has timetabled at 12-18 months.
The entire process is made all the more difficult since the main supply and exit route for materials is through Pakistan, a road which has been closed since November 2011 when a Nato air strike killed 24 people. Pakistan has demanded a high level apology from the US, besides renewed negotiations deadlocked over rates for transit of Nato containers through its territory.
Pakistan and US are still engaged in the negotiation process with the jury out on when routes could actually reopen. The Nato earlier this month also signed a pact with three countries for ferrying non-lethal cargo out of Afghanistan.
COMMENTS (5)
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ
Was that surprising? France appears to have said to the Afghans: If you do not appreciate our help, then we are content to go home. The fact is that Afghan Taliban go on killing Isaf troops in Afghanistan whenever they can. Why should foreign troops insist on helping the Afghans when the Afghans are determined to tell the foreign troops that they should take themselves away? The Afghan Taliban may have driven home their message. But, are they in a position that they can take on the responsibility of governance in Afghanistan? If the Afghan Taliban make a bid for power in Afghanistan, whether now or after December 2014, will the US really allow them? By then considerations of the US elections will have passed. The US, regardless of US public opinion, will have no option but to stand by the Afghanistan government, whoever may be heading it then. Pakistan will have no option but to keep off and let Afghanistan pursue its own stability and progress as it best may. Enough has happened in the last six months to drive home this message to Pakistan.
The right thing to do. The French may suffer a few taunts like, J. Leno making fun of them on the Tonight Show, but I'm sure they can live with that. After all they have history on their side.
He's a great man! I never wanted the "war loving" Sarkozy to win. French people aren't hostile like the Americans. Sarkozy did not represent the French, he represented a lobby (the war lobby). Thank God he's gone now.
Good riddance.