The European Union should establish a new frontier on the northern border of Greece, because an agreement with Turkey will not be enough to stop hundreds of thousands of migrants from coming to Europe, Hungarian Prime Minister Viktor Orban said on Friday.

Orban has gained support in Hungary with his tough stance on migration. His government has put up fences on the country's southern border to keep out migrants and asylum seekers fleeing war and poverty in the Middle East and Asia.

The barriers initially drew criticism from his European Union partners, but several countries, such as Slovenia and Austria, have since raised barriers of their own. Others have imposed checks within the EU's border-free Schengen zone to cope with the flow.

Orban said Germany, which welcomed a million migrants last year, has recently shifted towards "common sense" to slow arrivals. But Orban said nothing short of stopping more people entering would resolve the issue.

"I think the next line of defence that we need to build up lies on the northern border of Greece," Orban told public radio in an interview.

He said Bulgaria, one of Greece's northern neighbours, should be adopted into the EU's border-free Schengen zone, while Macedonia should be given financial support and other assistance so it could beef up its defences.

"I do not think that the deal with Turkey will be sufficient in itself," Orban said. Hungary erected fences on its southern borders to halt the flow of migrants.

In October, the EU offered Turkey a possible €3bn ($3.26bn) in aid, the prospect of easier travel visas and renewed talks on Turkey's joining the bloc, in return for its help stemming the flow of migrants to Europe.

"It is nice that (Turkey) has promised that there would be a line of defence there, but we need to build one of our own from our own resources on the northern border of Greece and stop, not slow down, but stop migration," Orban said.