"We all understand the difficulties associated with Brexit, but at the same time, it shows interesting prospects. Brexit could provide the EU governments with an opportunity to make a joint step forward in the defense area," Gentiloni told journalists at the meeting in Rome dedicated to the Brexit consequences.
He added that he expected London to provide certainty on timing and order of the United Kingdom's departure from the bloc.
Earlier in the day, foreign ministers of Estonia, Germany, Latvia and Lithuania agreed to enhance cooperation in the security sphere.
On June 23, the United Kingdom held a referendum to determine whether or not the country should leave the European Union. According to the final results, 51.9 percent of voters, or 17.4 million people, decided to support Brexit, while about 16.1 million opposed it.