GETTY Angela Merkel has struggled to deal with the refugee crisis

FREE now and never miss the top politics stories again. SUBSCRIBE Invalid email Sign up fornow and never miss the top politics stories again. We will use your email address only for sending you newsletters. Please see our Privacy Notice for details of your data protection rights.

Gerd Muller predicted the continent would face an even bigger refugee influx as migrants seek to escape "misery" in their homelands. The German development minister slammed the European Union for failing to control the crisis, saying the border-free Schengen zone has "collapsed". He also claimed the number of people living in Africa would "double in the coming decades", with Nigeria's population swelling from 186 million to 400 million.

Last year Chancellor Angela Merkel opened Germany's doors to an unlimited number of Syrian refugees. But she has since called for stricter laws regulating asylum seekers following a string of alleged sex attacks by gangs of migrants in Cologne. Mr Muller said: “The protection of external borders is not working. Schengen has collapsed. A fair distribution of refugees has not taken place."

GETTY Ms Merkel posing with a Syrian man at a refugee shelter

People are fleeing hunger, misery, violence Gerd Muller

The official urged Germany to invest in "education, training and prospects" to deal with the arrival of desperate refugees. He said: "People are fleeing hunger, misery, violence, and they see no future for themselves and their families. "But we live in a globalised world. We can not build fences around Germany and Europe. When people suffer, they will come. "

GETTY Cologne was rocked by a string of sex attacks on New Year's Eve

He also called for Europe to pay €10billion (£7.5million) to rebuild war-torn countries such as Iraq, Syria and Libya. He said: "All states must pay, especially those that receive no refugees." He added: "We need to rebuild towns and villages [in Syria], so that the refugees can now return there."