France's far-right leader Marine Le Pen says Europe must examine whether its immigration and security policies or economic austerity are partly to blame for the attacks in France.

Addressing the European parliament in Strasbourg Monday, Le Pen said: "Is the total opening of our national borders the real way to control fundamentalists who cross borders at will? Is it not the policies of austerity that have weakened our ability to respond? Or the disarming of our police and armies?"

Opening the parliament's four-day plenary session, European Parliament President Martin Schulz read out the names of the 17 victims of the attacks at the Charlie Hebdo newspaper offices and a Jewish supermarket in Paris.

Many lawmakers wore white T-shirts or held placards with "Je suis Charlie" written on them.