European Union countries are pushing to ramp up their defence industries and rearm their militaries after years of underinvestment in the face of Russia's invasion of Ukraine.

Diplomats said von der Leyen presented the estimate at a EU summit in Brussels during discussions on the gaps in the bloc's defence capabilities.

The head of the EU's executive did not, however, provide a detailed breakdown of what her projected sum covered.

"We didn't see spreadsheets, we didn't see details, this is pie in the sky money," one EU diplomat said.

There is also no clarity on how the EU would finance the investment.

Von der Leyen's European Commission was supposed to provide written options for raising funds at the summit, but instead she opted to deliver just a presentation.

There is a standoff over whether the EU should consider joint borrowing, similar to how it financed its recovery programme after the Covid pandemic.

"Several countries, including France and Estonia, are in favour of eurobonds," an EU official said. "But Germany and the Netherlands are against."

EU countries have already increased their defence spending in the decade since Russia seized Crimea from Ukraine in 2014.

That trend has accelerated since the invasion of Ukraine in 2022, with a sharp increase in the number of EU countries hitting NATO's target of spending two percent of gross domestic product on defence.

The bloc's defence agency says EU countries spent a total of 240 billion euros on defence in 2022.

The increases in EU defence spending in recent years have nonetheless been dwarfed by those of China and Russia.