BRUSSELS — European Commission head Jean-Claude Juncker called again Thursday for the bloc to build an army, saying a flock of hens posed more of a threat than its current military capabilities.

"A bunch of chickens looks like a combat formation compared to the foreign and security policy of the European Union," Juncker told a Brussels forum in typically lively language.

"I always call for a European army as a long-term project. It is not something you can build from scratch tomorrow morning," he said.

Juncker has consistently backed the idea that the EU's 28 member nations — all no strangers to a bloody, war-torn past — should accept a military arm, a need highlighted by the Ukraine crisis.

"A common army among the Europeans would convey to Russia that we are serious about defending the values of the European Union," he told Germany's Welt am Sonntag in March.

A joint EU force would also rationalize defense spending and drive further EU integration.

For many European Union states, however, defense is a no-go area, with Britain especially hostile to sacrificing what it sees as a core sovereign prerogative to Brussels.

Britain also insists that NATO, the US-led military alliance set up to hold the Cold War line against the Soviet Union, should remain the focus of European defense efforts.

Juncker told the forum that considering the current fragmented state of EU military readiness, it was perfectly "right that central and eastern European countries put their trust primarily in NATO."

"The 28 armies are just not up to it," he added.

EU leaders are due to review the bloc's security policy at a June summit to take on board the threat posed by a more assertive Russia and turmoil across North Africa and the Middle East.

Analysts say it is unlikely to lead to radical changes in the current very limited joint military operations undertaken by the EU, such as the Atalanta anti-piracy mission off the Horn of Africa.