Earlier this week, national delegations watered down a commitment to secure a deal on the budget by the end of the year.

EU money is key to "incentivize member states to go together for joint procurement, for joint development, for European development," the former Lithuanian prime minister argued. That's especially needed as defense spending remains too national-oriented and the defense industry too fragmented, he lamented.

"If we have less of those possibilities to incentivize member states, we shall not be able to change that situation, which is now really still not at the level we need in terms of defragmentation of European development," the commissioner said.