Luxembourg - Germany will extend migration controls along its border with Austria for an additional half year, Interior Minister Horst Seehofer has announced.

The decision - based on the argument that it is still too easy for migrants to move between EU countries and that external migration controls for the bloc are lacking - will be formally presented to the European Union later.

"The conditions for lifting the internal controls still don't exist," he said.

The decision means the controls will now be in place until May 11. They were instituted in 2015 after tens of thousands of migrants entered Germany via Austria after entering Europe through Greece or Bulgaria and then travelling on via the Balkan route.

Although the members of the EU have agreed to open borders as part of the Schengen agreement, several have implemented temporary controls since the 2015 migration crisis to ease immigration and to soothe political tensions.

The European Commission has been trying to put an end to border checks within the Schengen area, in part by beefing up controls on the EU's external borders.