PARIS (AFP) - France said on Wednesday that spying was "unacceptable between allies" after WikiLeaks said leaked documents showed that the United States wiretapped French President Francois Hollande and his two predecessors.

"It is unacceptable between allies," French government spokesman Stephane Le Foll said, shortly before an emergency meeting called by Mr Hollande with his security chiefs. "It is difficult to accept that between allies... there can be this kind of activity, particularly related to wiretapping linked to the president of the Republic."

"When we are fighting terrorism, one has trouble imagining or understanding what would motivate an ally to spy on his allies," he added. Mr Le Foll also tried to play down the controversy, saying it was not something that should trigger a major crisis. "There are enough dangerous crises in the world today," he said.

The French presidency said on Wednesday it "will not tolerate any acts that threaten its security". "Commitments were made by the US authorities," the Elysee Palace said in a statement, referring to promises by the US in late 2013 not to spy on France's leaders. "They must be remembered and strictly respected."

France is to convene a meeting of its defence council on Wednesday after the communications - classed as "Top Secret" and revealing spying on Mr Hollande and former presidents Nicolas Sarkozy and Jacques Chirac from 2006 to 2012 - were published online by WikiLeaks, in partnership with French newspaper Liberation and the Mediapart website.