Prague: Europe could suspend passport-free travel for two years under emergency measures as leaders warn the migrant crisis could destroy the European Union.

As they prepare for a summit to discuss a crisis plan in Amsterdam on Monday, EU leaders have warned there is now just six to eight weeks to save the Schengen zone from a chaotic collapse as hundreds of thousands of migrants in Turkey prepare for crossings in the northern hemisphere spring. About 2.6 million more people are forecast to arrive in the next two years.

Six countries – Germany, France, Sweden, Austria, France, Denmark and Norway – have already introduced border checks under emergency six-month powers that will expire in May in an attempt to halt the flow of migrants.

French Prime Minister Manuel Valls warned that the "very idea of Europe" was in "grave danger" unless the human tide is repelled.