PARIS -- French President Nicolas Sarkozy suspended military training and assistance for Afghan forces on Friday and said he would consider an early withdrawal from Afghanistan after an Afghan soldier shot and killed four French soldiers and wounded 15 others on a base in eastern Afghanistan.
The attack occurred during an especially deadly 24 hours for the international coalition, with six U.S. Marines killed in a helicopter crash Thursday night in southern Afghanistan.
All six Marines killed in the helicopter crash in Helmand province were based in Hawaii, U.S. Rep. Colleen Hanabusa said Friday.
The Taliban said it shot down the helicopter, but NATO said no enemy activity was reported in the area at the time.
The gunman's attack on French troops was the latest in a series of episodes in which Afghan soldiers or police officers, or insurgents wearing official uniforms, have opened fire on soldiers of the U.S.-led coalition in Afghanistan.
The killings are aimed at sapping Western morale and hastening withdrawal of foreign troops from Afghanistan sooner than an agreed NATO deadline of the end of 2014, when Afghan forces are supposed to be ready to defend the country on their own.
With many European countries facing economic pressures at home, such attacks by Afghan soldiers on foreign troops have added to public questioning of the value of continued involvement in Afghanistan.
If France were to reduce its troops early or precipitously it could spur other countries to follow suit, Western and Afghan officials warned.
France has been a firm ally of the United States in Afghanistan, with the fourth-largest contingent of troops, according to NATO figures, and 82 French soldiers have died.
Facing a fierce battle for his re-election, Mr. Sarkozy said security must improve in Afghanistan if France is to stay.
"If security conditions are not established clearly, then the question of an early return of the French army will arise," he said. "It will be a difficult decision that we will have to take in the coming days, but I have to do it while being able to face the French public and our soldiers."
France and its army are "at the side of its allies, but we cannot accept that a single one of our soldiers be killed or wounded by our allies," he said. "It is unacceptable; I will not accept it."
Mr. Sarkozy has rejected U.S. requests to add to the 3,900 French personnel in Afghanistan, according to NATO.
Although he has withdrawn forces in parallel proportion with the United States, he is widely expected to accelerate those withdrawals. He has said he will pull out 1,200 personnel this year.