The record influx of refugees into Germany is the country's biggest challenge since its reunification over two decades ago, Vice Chancellor Sigmar Gabriel said on Sunday, criticising the passiveness of other European nations.

The number of asylum seekers in Germany is expected hit 800,00 2015, as people from Africa and the Middle East flow into Europe fleeing poverty and war.

Sigmar told public broadcaster ARD that the refugee issue "is a collective duty, the biggest challenge since reunification" in 1990, which forces the country to "to do much more" and "radically change its policies."