AFP, PARIS - France could send "several hundred" extra soldiers to join the NATO force in Afghanistan, Prime Minister Francois Fillon said Tuesday, adding that details of the mission had not yet been decided.

Fillon made the announcement during a stormy parliamentary debate on the new deployment, after President Nicolas Sarkozy last week promised more French troops for the alliance's shaky mission in Afghanistan.

Sarkozy is to announce details of the French reinforcements at a North Atlantic Treaty Organisation (NATO) summit in Bucharest from Wednesday to Friday.

"The numbers could be in the order of several hundred extra soldiers," Fillon said Tuesday, adding that France would only send the extra troops if NATO accepted certain conditions imposed by Paris.

These included a commitment by NATO to "maintain its efforts in the long-term," "a shared political strategy," and "increased training" of Afghan troops. Sources in Paris have said 1,000-plus troops could be sent to shore up the current 1,600-strong French contingent that is deployed mostly in Kabul and the surrounding area.

Some 100-200 French special forces could also take part. France's opposition Socialists, bolstered by an opinion poll showing 68 percent of the French disapprove of Sarkozy's decision to send reinforcements, called for a parliamentary vote on the mission.

But Fillon rejected the call, saying the decision to take part in the NATO mission in Afghanistan was taken by a previous government in 2001 without one. He argued that Kabul could fall to Afghanistan's Taliban militia unless the NATO mission was strengthened, resulting in "real defeat for all those who defend freedom."