DANISH Prime Minister Mette Frederiksen called for European countries to ramp up military spending today, accusing Russia of waging a “hybrid war” against Europe.

“There is only one country that is willing to threaten us and it is Russia,” she declared, although the United States has explicitly threatened to annex the Danish territory of Greenland while Russia has not issued any threats against Denmark.

Ms Frederiksen suggested Russia was behind drone incidents at Danish airports and military bases.

Unidentified drones forced the closure of Copenhagen airport a week ago, causing major disruptions.

France, Germany, the Netherlands, Sweden and Britain sent aircraft, ships and air defence systems to Denmark ahead of the talks, as did Ukraine, which is at war with Russia. Ukrainian President Volodymyr Zelensky is due to address the EU summit by video link.

“I want us to rearm. I want us to buy more capabilities. I want us to innovate more, for example on drones,” the Danish PM said. "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.”

On September 10 several unarmed Russian drones breached Poland’s airspace. Russia says this was accidental, and Belarus gave Poland advance warning that the drones had gone off course, but many European countries view it as a deliberate test by Russia of their air defences.

The summit will consider using frozen Russian assets to help Ukraine, potentially provoking international lawsuits, and whether recent belligerent talk by US President Donald Trump indicates he may be shifting to a more hostile position towards Russia.