KABUL (AFP) - French President Nicolas Sarkozy on Wednesday told French soldiers mourning 10 comrades killed by the Taliban that their work in Afghanistan was essential for the "freedom of the world" and must continue. Sarkozy travelled to Kabul with his Defence Minister Herve Morin and Foreign Minister Bernard Kouchner for a lightning visit to show support after the 10 were killed and 21 others wounded in a battle with Taliban rebels this week. It was the deadliest toll in ground fighting for international forces sent to Afghanistan after the Taliban regime was routed in late 2001, and the heaviest for French troops in 25 years. "I came to tell you that the work that you are doing here is essential," Sarkozy told the troops at their base at Camp Warehouse on the outskirts of Kabul. "The best way to be loyal to your comrades is to continue your work, is to raise your heads, to be professional." Sarkozy visited a morgue where the 10 bodies were held before being repatriated, and spoke to survivors of the battle, including some of the wounded being treated in a camp hospital. "Why are we here? It is because here we play a part in the freedom of the world. Here we are fighting against terrorism," he said. An official said Nato will "look into" a report that French soldiers were hit by planes from the alliance that had come to help them escape a Taliban ambush in Afghanistan. "I have nothing substantive to confirm or deny this particular suggestion," the official told AFP. He was responding to a report in France's Le Monde newspaper that quoted French soldiers who had survived the ambush Monday near Kabul saying they came under fire from Nato planes that had come to help them escape. The soldiers said that once they had fallen into the ambush they had to wait for four hours before any back-up was sent. When Nato planes finally arrived to help them they sometimes missed their target and hit French troops, the paper quotes the soldiers as saying. There were new barbs in France Wednesday, with politicians and commentators questioning why the country had got itself involved in the Afghan "quagmire." The French army and ISAF in Kabul meanwhile refused to comment on a report in Le Monde newspaper quoting French soldiers who had survived the ambush saying they came under fire from Nato planes that had come to help them escape. "A war without end," said a headline in the left-wing Liberation newspaper, whose editorial nonetheless said that for France and the 40 other nations with troops in Afghanistan, "the worst solution would obviously be withdrawal." Far-right leader Jean-Marie Le Pen said, "Our soldiers should not be killed for Uncle Sam". But Le Pen aside, the debate across the political spectrum focussed on the strategy of the Nato-led force in Afghanistan and not on pulling out the troops. President Nicolas Sarkozy's decision in April to send an extra 700 troops to Opinion polls showed that a large majority of French opposed the move, with many fearing France would get bogged down in an unending war whose aims were unclear or unattainable. Many commentators and political leaders now see Afghanistan - which under the Taliban let Al-Qaeda leader Osama bin Laden operate freely on its territory - as the frontline in the fight against international terrorism. Deputy Pierre Lellouche of Sarkozy's right-wing UMP party, tasked with writing a report on Afghanistan, said Nato's strategy "was failing, both on the political and the military level" and must be fully overhauled. The opposition Socialist leader Francois Hollande said that after the latest French casualties, for whom a day of national mourning was to be held Thursday, the public must be told "what exactly our soldiers are doing in Afghanistan and how long they will be doing it for." "The question now," said Bruno Jeanbart of the polling institute OpinionWay, "is whether public opinion will be reinforced in its feeling of the uselessness of the French presence in Afghanistan or will the public rally round their soldiers in difficulty, and become more favourable to it."