EU leaders are meeting in Copenhagen under pressure to boost European defence after a series of Russian incursions into EU airspace, and days after drones targeted Danish airports.
Danish Prime Minister Mette Frederiksen told reporters that from a European perspective there is only one country... willing to threaten us and that is Russia, and therefore we need a very strong answer back.
The incursions have become most acute for countries on the EU's eastern flank such as Poland and Estonia.
A number of member states have already backed plans for a multi-layered drone wall to quickly detect, then track and destroy Russian drones.
Denmark has beefed up security for the summit, banning all civilian drone flights until Friday and placing heavy restrictions on traffic in Copenhagen.
Denmark is also hosting a broader European Political Community summit on Thursday and international allies have lent support to ensure both events pass without incident.
Copenhagen airport, followed by several Danish airports and military sites on the Jutland peninsula, faced drone disruption last week.
Ten allies are providing anti-drone and surveillance support, according to Denmark's military. A German frigate has also docked in Copenhagen.
As host to dozens of European leaders over two days, Denmark will want to fend off any more unwelcome surprises in its air space.
Danish police have not found any evidence that Russia was behind last week's drone disruption, but Frederiksen linked it explicitly to other hybrid attacks such as Russia's drone incursion over Poland.
The war in Ukraine is very serious. When I look at Europe today I think we are in the most difficult and dangerous situation since the end of the Second World War - not the Cold War any more.
Sweden has loaned powerful radar systems to its neighbour for the week, and Ukraine's Volodymyr Zelensky said Kyiv is sending a mission to Denmark for joint exercises to provide Ukrainian experience in drone defence.
German Chancellor Friedrich Merz said ahead of the summit that airspace incursions were getting worse and it was reasonable to assume the drones are coming from Russia.
Underlining the seriousness of the situation, he stated, We are not at war, but we are no longer at peace either. We must do much more for our own security.
The idea of a drone wall was reiterated by European Commission President Ursula von der Leyen, emphasizing the need for Europe to bolster its defenses against emerging threats.
A senior EU diplomat noted that there are still questions over financing the plan and command and control, but pointed to a growing recognition that Europe needs to be more agile amid the heightened threat from Russia.
The EU is slated to unveil a roadmap for strengthening its military capabilities in the coming years, focusing on joint procurement and collaboration with NATO and Ukraine.
