France is suspending all training operations for Afghan troops and has threatened to pull its entire force out of Afghanistan early after an Afghan soldier shot and killed four French soldiers on Friday.

The attack was one of the most deadly for French forces in the 10 years they have been serving in the international force in Afghanistan.

The U.S.-led coalition said an Afghan soldier shot and killed four NATO troops in Kapisa province in eastern Afghanistan.

'The French army is not in Afghanistan so that Afghan soldiers can shoot at them.' —French President Nicolas Sarkozy

French President Nicolas Sarkozy confirmed the deaths, which bring to 82 the number of French troops killed during the Afghan campaign.

"From now on, all the operations of training and combat help by the French army are suspended," Sarkozy said in reaction to the deaths.

The French have played a big role recently in training Afghan troops ahead of the expected pullout in 2014 of the around 4,000 French troops stationed there.

"If the conditions of security are not clearly restored, then the question of an early withdrawal of the French army would arise," Sarkozy said, without elaborating.

"The French army is in Afghanistan at the service of the Afghans against terrorism and against the Taliban. The French army is not in Afghanistan so that Afghan soldiers can shoot at them," Sarkozy said.

Afghan President Hamid Karzai is expected to visit Paris next week.

In an annual speech on French diplomacy, Sarkozy also urged stronger, more decisive sanctions against Iran over its nuclear program.

He called on Russia and China to help increase pressure on the Islamic Republic.

"I say to our Chinese friends and to our Russian friends: help us to guarantee peace in the world. We clearly need you," Sarkozy said.

China and Russia remain opposed to tightening sanctions against Iran.

France wants the entire European Union to impose an embargo on Iranian oil and freeze the international assets of Iran's central bank to force it to halt the suspected development of nuclear arms.

On Syria, Sarkozy said France would continue its policy of non-interference.

"No one more than myself has tried with sincerity to reach out to Bashar Al-Assad (Syrian leader). But at some stage, everyone has to face the reality. And France will not remain silent in front of the Syrian scandal," he added.