BUDAPEST (Reuters) - Hungary's Prime Minister said the European Union should round up and deport all illegal immigrants and assemble them in EU-supervised refugee camps beyond the bloc's borders where they can then file for asylum.

"This could be an island, it could be a coastal area in North Africa, but the security and supplies of that area must be guaranteed by the EU in its own interest," Viktor Orban told the news website Origo in an interview published on Thursday.

The firebrand premier has provoked controversy with a tough rhetoric about migrants and a razor wire fence along Hungary's southern border, as well as a referendum against mandatory resettlement quotas on Oct. 2.

"Those who came illegally must be rounded up and shipped out," Orban said.

"We must set up large refugee camps outside the EU, with armed security and financial support provided by the Union. Everyone who came illegally must return there. There they can file for asylum."

He said this was a "grave moral task" that was the only alternative to the migrants staying in Europe and being relocated around the continent, creating further problems. Resettlements were an exercise in futility as those who wanted to be in Germany would promptly return there after resettlement.

"There is only one solution that befits everyone, including us who are not yet in trouble because we defended ourselves and countries like Germany which are in trouble: Taking (migrants) out of the Union."

He reiterated that the external borders of the EU must be strengthened to prevent a repeat of the 2015 flow of migrants.

"Borders must be used, because they protect us," he said. "Some imagine a globe without borders...I am one of those who would not like to see the civilization of the world change."

(Reporting by Marton Dunai; editing by Ralph Boulton)