French President Francois Hollande on Tuesday said he could envisage a six-month extension to France's state of emergency in the aftermath of the Nice terror attack.

"There has been an attack and at this point we don't know if there will be others," said Hollande, adding "it is my duty, and that of parliament, to extend the state of emergency for three months, although I am open to a further extension of three months."

Parliament on Tuesday was to debate extending the country's state of emergency for a fourth time after the Bastille Day truck attack in Nice that left 84 dead.