Ten French soldiers were killed Tuesday and 21 others were injured in a gun battle with insurgents near the Afghan capital, Kabul, French President Nicolas Sarkozy's office confirmed in a statement.

About 100 insurgents ambushed the group of French parachutists Monday during a joint reconnaissance mission with the Afghan National Army, said the president's office. Media reports said the battle, which continued into Tuesday, was in an area about 55 kilometres east of the capital.

The death of the 10 soldiers marks the biggest single loss of life for any international forces engaged in combat in Afghanistan in more than three years, officials said Tuesday.

In the statement, Sarkozy said he would travel to Afghanistan on Tuesday evening "to assure [the soldiers] that France is at their side."

"My determination is intact," the president said. "France is determined to continue the fight against terrorism, for democracy and freedom."

French soldiers with the International Security Assistance Force are seen on patrol as Afghan boys pass by on the outskirts of Kabul in this March 2008 file photo. (Rafiq Maqbool/Associated Press)

France has about 1,600 troops in Afghanistan, and Sarkozy has pledged to send 700 more soldiers by the end of the year to help the NATO-led forces.

Speaking to reporters in Hamilton, Ont., Canadian Prime Minister Stephen Harper expressed his condolences for the loss of life Tuesday.

"It's a very sad day for France and I think they know we all feel that," he said, adding he was proud of France for its military contribution.

"We believe it's essential for all NATO countries to stay the course so we accomplish our objectives of creating a stable environment in Afghanistan that is not a threat either to its people or people elsewhere in the world."

Injured Canadian 'in good condition' after attack

Meanwhile on Tuesday, a suicide bomber attacked a joint Canadian-Afghan patrol in the southern province of Kandahar, killing an Afghan interpreter and injuring a Canadian soldier and a local boy, the Canadian military said.

The attack occurred at 7:45 a.m. local time in a crowded marketplace area near the Panjwaii district centre of Bazaar-e-Panjwaii, a spokesman said.

The injured Canadian soldier and the boy were airlifted to the hospital at Kandahar Airfield, where they are being treated. The soldier is in good condition while the boy is in serious but stable condition, the spokesman said.

The soldier's identity is not being released.

Canada currently has about 2,500 soldiers deployed in Afghanistan. It began the mission in early 2002, months after a U.S.-led invasion toppled the Taliban government.

7 militants killed in thwarted attack on U.S. base: NATO

Also on Tuesday, at least seven militants, including six suicide bombers, were killed as they joined dozens of gunmen in trying to storm a main U.S. base in eastern Afghanistan, NATO said.

The dead body of a suicide bomber is seen in the site where he detonated himself in Khost city, eastern Afghanistan, on Tuesday. (Nashanuddin Khan/Associated Press)NATO soldiers attacked the group of militants as they gathered about one kilometre from the perimeter of Camp Salerno in Khost city, south of Kabul and near the Pakistan border, the alliance said in a news release.

Three insurgents detonated their vests after being surrounded outside the base, NATO said, while three others were killed before their explosives went off. There were no casualties among NATO forces, the alliance said.

Arsallah Jamal, the governor of Khost province, said the militants failed to gain entry into the base and that coalition troops used air strikes to push back the assailants to a nearby village.

The attack on Camp Salerno came a day after a suicide bomb outside the base killed 10 civilians and wounded 13 others.

NATO also announced that British soldier was killed Monday in an insurgent attack while on patrol in southern Afghanistan.

With files from the Associated Press