France will seek to keep its state of emergency until a "total and global war" against so-called Islamic State (IS) is over, Prime Minister Manuel Valls has told the BBC.

The measures were introduced after the IS-led Paris attacks on 13 November and then extended for three months.

Such a move gives police more power to conduct raids and impose house arrests.
Mr Valls also warned that Europe's migration crisis was now putting the European Union itself at grave risk.

German Chancellor Angela Merkel is due to hold talks with Turkish Prime Minister Ahmet Davutoglu in Berlin .

EU countries hope Turkey will help to control the flow of migrants reaching the EU from Syria and other conflict zones.

Interviewed by the BBC's chief international correspondent, Lyse Doucet, at the World Economic Forum in Davos, Switzerland, Mr Valls said France was "at war", which meant "using all means in our democracy under the rule of law to protect French people".

When asked how long he envisaged the state of emergency remaining, Mr Valls said: "The time necessary. We cannot always live all the time in a state of emergency."

"As long as the threat is there, we must use all the means," he said, adding that it should stay in place "until we can get rid of Daesh", using an acronym for IS.

"In Africa, in the Middle East, in Asia we must eradicate, eliminate Daesh," he said. "It is a total and global war that we are facing with terrorism," he added. "The war we are conducting must also be total, global and ruthless."