Germany's cabinet has agreed new draft laws against forced marriages and tough measures against immigrants who fail to integrate into society, amid a fierce debate about immigration in the country.

Forcing someone into marriage will now be considered a criminal act in itself, punishable by up to five years in prison, under the legislation drawn up by Chancellor Angela Merkel's government.

Previously, forced marriage had been considered under the law as a particularly severe form of coercion.

The new legislation also aims to make it easier for women taken abroad for a forced marriage to return to Germany.

"Forced marriage is a problem in Germany that should be taken seriously and which is increasingly in the public eye," said Interior Minister Thomas de Maiziere in a statement.

"In order to act against forced marriage in a tougher way than before, it will be considerable a punishable offence in its own right.

"In this way, we are also acting against the incorrect view that it is a tolerable tradition from earlier times or from other cultures," added the minister.

Germany has been rocked in recent years by several cases of young girls being coerced into marriages, the majority Muslim.

The cabinet also sought to enforce action against immigrants in Germany who do not follow so-called "integration courses" to help them adapt to life in the country.

De Maiziere has estimated this applies to around 10 to 15 percent of immigrants in Germany.

Authorities will be obliged to check whether immigrants have followed such a course before considering an application to extend their stay in Germany. Refusal to follow courses could result in applications being rejected.

"Being able to speak German, being familiar with everyday life in Germany, as well as German law, culture and history are the keys for the successful integration of foreigners in Germany," de Maiziere said.

The move came amid a ferocious debate in Germany about immigration and the country's "multi-cultural" society.

The debate was fuelled by Thilo Sarrazin, a central banker who said Germany was being made "more stupid" by immigrants, and then further inflamed by Merkel who judged multiculturalism had totally failed.

The popularity of a book by Sarrazin and a recent study showing strong anti-foreigner sentiment have raised fears about a right-wing populist attracting significant support, although no such figure has yet emerged.

There are also concerns that a lack of integration of Germany's four million Muslims was helping create homegrown Islamic extremists.

The draft law must now be debated in parliament, where Merkel's centre-right coalition holds a majority.

Berlin also aims to sign off on a bill in December that would see more foreign diplomas formally recognised, something which would help employers in Europe's biggest economy find badly needed qualified workers.