The threat to Europe's airspace has been heightened by unidentified drone flights in recent days that have shut airports in Denmark.

EU chief Ursula von der Leyen made a first call for a "drone wall" in a keynote speech earlier this month, hours after NATO shot down Russian drones in Poland.

She said it should be "a European capability developed together, deployed together, and sustained together, that can respond in real time."

"This is not an abstract ambition," von der Leyen said.

European defence commissioner Andrius Kubilius will seek to put flesh on the hastily-drawn up proposals when he holds video talks Friday with officials from some 10 EU countries.

Those involved are mostly along the EU's eastern border with Russia and Ukraine, although Denmark was added to the list after the drone incidents there.

Ukraine -- which has developed a raft of capabilities to detect and shoot down Russian drone swarms more cheaply -- will also take part.

EU officials concede that for now details remain vague on what the initiative could look like.

The first steps will likely focus on trying to deploy more sensors along the EU's long eastern frontier, officials said.

It would likely take much longer to develop an integrated system to take down the drones, they said.

NATO's response to the Russian drone incursion in Poland showed up the gaps in the alliance's arsenal for tackling that threat.

NATO had to use top-of-the-range fighters firing costly missiles to shoot down a handful of cheap Russian drones.

The alliance has rushed more hardware to its eastern flank in the wake of the incident, but still lacks the sort of low-cost capabilities Ukraine uses.

The "drone wall" proposal is part of Europe's broader push to bolster its defences in the face of the threat from Russia.

Kubilius has said the programme should be one of the new flagship defence projects that the bloc is working on.

EU leaders are set to debate the defence push -- and potential new initiatives -- at a summit in Copenhagen next week.