Germany has promised to deport a record number of migrants who have their asylum applications rejected this year, topping the 80,000 deported in 2016.

Chancellor Angela Merkel's Chief of Staff, Peter Altmaier, told the Bild am Sonntag newspaper that nearly half of the 700,000 asylum requests submitted in 2016 had been rejected.

There is now a move to deport asylum seekers once their applications have been rejected as well as foreigners who have committed crimes, as Merkel faces a backlash following her decision in 2015 to open German borders to refugees.

"We sent home 80,000 last year whose asylum applications were rejected - that's a record," said Altmaier, who is also the government's coordinator on refugee affairs.

"And the number will rise again further. There were some 700,000 asylum applications in 2016 and nearly 300,000 were rejected. We'll be sending these people home quickly because if we don't, it will damage our credibility as a state based on the rule of law," Reuters reports him saying.

Altmaier added that it was important to send these people home immediately to maintain a high level of public support for the asylum system.

Those who seek asylum need to show they would face persecution at home. Previously many of the migrants whose applications were rejected were still allowed to remain in the country temporarily.

Deutsche Welle noted that those who are denied the right to remain in Germany usually do not leave the country unless they are deported.

Furthermore, under the German constitution and international law, failed asylum seekers cannot be sent back to places where they are in danger. The German government therefore needs to show that the asylum seekers' countries of origin are safe to send them back to.

Deutsche Welle noted that it was far easier for the government to reject applications who come from countries that have officially been deemed safe.

In a bit to hasten the process of deporting failed asylum seekers, Germany signed a treaty with Afghanistan in October 2016 that covered safety guarantees and the acceptance of temporary identification documents.

The government is now hoping to sign similar deals with the Maghreb countries, DW says.

Merkel's chief of staff also said that he hoped the upper house of parliament will soon agree to change the status of Tunisia, Algeria and Morocco to allow the automatic and swift rejections of asylum seekers from these countries.

He further noted that asylum seekers can live safely in some parts of Afghanistan.

Government figures show that the largest number of people deported in the first half of 2016 were sent back to Albania, Kosovo and Serbia - nations officially considered "safe countries of origin".

According to statistics, Deutsche Welle said three-quarters of asylum applications in 2016 came from Syria, Afghanistan or Iraq.