"Europe needs to assume greater responsibility for its own defence," European Council chief Antonio Costa wrote in a letter inviting EU heads of state and government to the talks at Limont Castle, an hour outside Brussels.

"I believe we share a similar assessment of the threats Europe is facing," Costa told member states -- with Russia's aggression against Ukraine spelling the return of "high-intensity war" to the continent, along with a surging threat from hybrid and cyber-attacks against member states.

"Peace in Europe depends on Ukraine winning a comprehensive, just and lasting peace," Costa underlined, warning that the geopolitical outlook for the bloc would "remain challenging in the foreseeable future".

The talks will come at a crucial juncture, with key Ukraine backers Britain and the EU warily eyeing Trump's promises to put a swift end to the conflict after taking power on January 20.

The EU's foreign policy chief Kaja Kallas reiterated last week that she hopes the United States will maintain its support for Kyiv -- but that if not, Europe was ready to take the lead.

Costa extended an official invitation last month for British Prime Minister Keir Starmer to join the February meet -- as his Labour party pushes to "reset" relations with the EU after years of post-Brexit rancour.

NATO's secretary general, Mark Rutte, will also attend to "discuss the most pressing defence-related issues, in particular our support for Ukraine, as well as EU-NATO cooperation", Costa said.

"We have a common interest in doing more and better at European level," he wrote in his letter to leaders.

- Defence partnerships -

Talks will focus on defining priorities for boosting Europe's defence capabilities, on how to accelerate private financing and better mobilise public funds for defence, and how to deepen partnerships including with non-EU European partners.

In terms of EU-UK cooperation, defence and security are seen as areas where London and Brussels could work closer together, with Britain eyeing access to EU programmes to boost weapons production.

Costa said Starmer would take part in a working dinner -- his first meeting with all 27 leaders -- that would also lay the groundwork for an EU-UK summit take place later this year.

"The UK is a key partner for the European Union, notably in the field of defence," Costa stressed.

The February meeting will feed into a planned white paper on the future of European defence, with the topic to be tackled again at a June EU leaders summit, Costa said.