Europe could see the return of national borders of walls and barbed wire if it fails to control its external borders, France's President has warned.
Speaking at a joint session of parliament in Versailles, François Hollande said failing to protect Europe's borders "would mean the dismantling of the European Union".
"Daesh is the enemy of Europe, and Europe cannot live with the idea that the crises that surround it don't have an effect on it. The migrant question is directly linked to the crisis in Syria and Iraq," he said, using the Arabic-derived term for Isis.
"If Europe doesn't control its external borders it is the return of national borders of walls and barbed wire as we've seen today.
"This would mean the dismantling of the European Union."
He later discussed the government's powers under the French constitution, saying "we are at war but it is a different type against a new sort of enemy."
As early as Wednesday, the French Parliament will consider a law to extent the current state of emergency for three months.
They will also greatly extend powers of search and house arrest.
Mr Hollande said the world "has to be pitiless", adding "cruel to say it but French people killed other French people on Friday. There are some people living in our territory who have been turned into terrorists. Some go to fight in Syria and Iraq and manage to return."
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