Europe's refugee crisis has revived plans for a controversial pan-EU border and coast guard force to patrol countries like Greece and Italy which are struggling to cope with the wave of migrants.

But analysts suspect frontline nations will resist ceding sovereign border control rights to other European Union states and that Brussels will have to settle for a far less ambitious proposal.

"This is a little bit like calling for a European army. It's a nice idea but it's a very long shot," Marc Pierini of the Brussels-based think tank Carnegie Europe, who is a former EU ambassador, told AFP.

"What we can hope for is a mechanism by which national coast guards would be coordinated, reinforced with EU financial means, but essentially leaving the task to member states," he added.

Indeed the idea of German, French or Belgian officers joining their Greek counterparts on boats plying the waters around the Aegean islands or at border crossings may be too much for most Greeks.

But Europeans are groping for a coordinated solution to the worst migration crisis since World War II, which has seen more than half a million people enter the bloc this year, sparked largely by the war in Syria.

Most come by sea, while some cross Turkey's land borders with Greece and Bulgaria. And a growing number are coming by land over the Balkans after first landing in Greece and then moving on to Hungary and Croatia.

- Talks next week -

Brussels sources said the European Commission, the executive of the 28-nation bloc, is consulting with member states about drafting a plan by the end of the year for a European System of Border Guards.

The movement of migrants into Europe K. Tian/JM.Cornu/J.Jacobsen, AFP

The plan, launched by European Commission chief Jean-Claude Juncker last month, is to be debated next Thursday by EU home affairs ministers.

EU leaders at an emergency summit last week threw their weight behind calls from Polish European Council President Donald Tusk to "regain control" over the external borders.

This is part of a broader drive to relocate 160,000 asylum seekers throughout the bloc from overstretched Greece and Italy and set up reception centres in those countries that admit refugees fleeing war but reject migrants seeking jobs.

A senior EU source said they expected the border guard plan to be the next big issue that leaders would have to confront after the relocation deal.

The border guard system would be led by Frontex, the Warsaw-based EU border protection agency.

In a speech to the European Parliament recently, Juncker called on EU states to "strengthen Frontex significantly and develop it into a fully operational European border and coast guard system."

Frontex has already tripled the resources -- aircraft, helicopters, patrol boats and guards -- for the Triton operation off southern Italy as a response to mass migrant drownings.

The new focus on external borders responds to fears that Europe's cherished Schengen passport-free zone could buckle as states reintroduce border checks to stem waves of migrants inside the bloc, many of whom are heading for Germany.

- 'Laughed in my face' -

A refugee throws a bottle of water towards Hungarian riot police after they used water cannon to push back refugees at the Hungarian border with Serbia near the town of Horgos on September 16, 2015 Armend Nimani, AFP

Alain Cadec, a French member of the European parliament, said he has been pushing since 2010 for a pan-European coast guard responsible for 44,000 kilometres (27,000 miles) of coastline.

"At the time, everybody laughed in my face," Cadec told AFP.

But Pierini, who tackled Mediterranean smuggling of migrants a decade ago when he was EU ambassador to Tunisia and Libya, said smugglers know how to outfox many border measures so a big border guard scheme may be redundant anyway.

"They are much faster than any public service and therefore we have to be careful not to invent under the pressure of this migratory crisis a huge massive, costly mechanism," he said.

Axel Dyevre, director of the Brussels office of the European Strategic Intelligence Company, thinks the EU may be able to harmonise the work of around 300 border-related bodies as well as arrange for joint missions by member states.

But "a force of armed coast guard vessels manned by European officers under commission command has no chance of seeing the light of day," he told AFP.