The US's ongoing withdrawal of key military assets from Europe will cost €500 billion to replace, European Commissioner for Defence Andrius Kubilius said on Tuesday, warning that the bloc must work together and start producing the “big items” it needs to defend itself – or suffer the consequences.

"We have big defence industrial challenges at the moment for the European Union,” he said at a public event in Brussels. “German experts just recently calculated that it will cost around €500 billion for Europeans to build those strategic enablers and to replace American strategic enablers now located on the European continent."

"We need (a) big change of our policies and practices in defence now."

These assets traditionally include air defence, reconnaissance, strategic airlift and more. The defence commissioner, however, grounded his argument in a paper from the German Kiel Institute that estimates €500 billion will need to be spent over the next decade across 10 key areas.

“Significant progress toward sovereignty can be achieved within 3-5 years, and a high degree of autonomy can be reached in most areas within 5-10 years – provided these are pursued as a political priority through a concerted European effort,” the paper argues.