The EU will set up its own military headquarters, ministers agreed on Monday.
The entity will initially have some 30 staff and fit together with the bloc’s existing military structures.
“Today we decided to establish a MPCC (Military Planning Conduct and Capability facility) which will command the EU’s non-executive military missions,” she told reporters.
But top EU officials, including Mogherini, have had to repeatedly issue reassurances that the bloc is not going to undercut NATO as the primary defence for Europe.
Besides Britain, many of the former Communist states of eastern Europe such as Poland and Hungary have argued consistently that NATO must come first, given the need for US support in facing a more assertive Russia.