COPENHAGEN, Oct 1 (Reuters): European Union leaders will discuss proposals for a "drone wall" to protect the continent at a summit on Wednesday in Copenhagen, just days after airspace intrusions by unidentified unmanned aircraft forced a temporary closure of Danish airports.

The summit will also be the first opportunity for leaders of the EU’s 27 countries to debate a proposal to use Russian assets frozen in Europe to fund a loan of 140 billion euros ($164.37 billion) to Ukraine.

France, Germany, Sweden, Norway, the Netherlands, Britain, Finland and Ukraine have committed troops and anti-drone systems to help Denmark protect the leaders, many of whom have accused Russia of brazen violations of European airspace with recent incursions by drones over Poland and fighter jets over Estonia.

Denmark has stopped short of saying who it believes is responsible for the incidents in its airspace last week, which disrupted air traffic at six airports, but Prime Minister Mette Frederiksen has suggested it could be Moscow.

Russia has denied responsibility for the drones over Denmark, disputed that its fighter jets entered Estonian airspace and said it did not intend to send drones into Poland.

But the incidents prompted European leaders to step up calls to bolster the continent’s defences and boost support for Ukraine in its fight against Russia’s invasion. U.S. President Donald Trump has demanded the EU take more responsibility on both fronts.

At the summit, the leaders will discuss proposals for four flagship defence projects including a “drone wall” – a network of sensors and weapons to detect, track and neutralise intruding unmanned aircraft.

European Commission President Ursula von der Leyen floated the idea last month, just hours after some 20 Russian drones entered Polish airspace, although officials say it had been in the works before then.

The Commission, the EU’s executive body, has not yet produced a detailed plan, leaving open questions about the cost and practicalities. But NATO Secretary General Mark Rutte praised the idea on Tuesday as “timely and necessary”.

The incursion into Poland exposed gaps in Europe’s ability to defend against drones, officials and analysts said. NATO forces deployed fighter jets, helicopters and a Patriot air defence system in their response, shooting down several drones.

“We cannot spend millions of euros or dollars on missiles to take out drones, which only cost a couple of thousand dollars,” Rutte said.