Former Italian premier and former European Central Bank President Mario Draghi warned that the European Union's sovereignty is at risk because of its inability to act decisively as he addressed a high-level conference in Brussels on Tuesday on the progress made since he presented his report on boosting the bloc's competitiveness a year ago.

"One year on, Europe is in a more difficult situation," he said.

"Our growth model is fading.

Vulnerabilities are increasing and there is no clear path to finance the investments we need.

"We have been painfully reminded that inaction threatens not only our competitiveness, but also our very sovereignty.