The goal of PESCO is to further increase defense cooperation between member states, to encourage larger defense investments, to facilitate the availability of military capabilities for European Union operations, to strengthen defense cooperation between member states, and to decrease capability gaps. On Monday, 23 of the EU's 28 member states signed up to the program, known as permanent structured cooperation, or PESCO.
Britain, Denmark, Ireland, Portugal and Malta did not join the pact, but the initiative remains open to any country that decides to sign up later, officials said.
Mogherini said countries have already submitted more than 50 joint projects in the fields of defense capabilities and military operations.
"The real problem is not how much we spend, it is the fact that we spend in a fragmented manner", Mogherini said.
This has led to unease by European allies that the U.S. was not committed to the alliance's mutual defence pact.
Germany wanted as many countries as possible to sign up but for it to undertake more modest schemes, and Berlin's vision looks to have won the day.
"The Germans say respect unity and proceed modestly at the start with... all these little projects - they won't help the EU's independent capacity", Mauro told AFP.
It foresees the possibility of a number of European Union member states working more closely together in the area of security and defence.
German Defense Minister Ursula von der Leyen said it was important for Europe to begin to stand on its feet when it comes to security and defence - "especially after the election of the US President (Donald Trump)".
Under PESCO, EU countries will commit to increase military spending, but not to specifically adhere to NATO's bottom line of moving towards 2 percent of gross domestic product for defense budgets by 2020. "It has no chance of working".
Estonian Defense Minister Jüri Luik said the main focus of the new initiative would be defense industries as "collective defense will always remain in North Atlantic Treaty Organisation". The EU, she said, has tools to fight hybrid warfare - the use of conventional weapons mixed with things like propaganda and cyber-attacks - that the American-led military alliance does not have at its disposal. At launch the focus will be project-driven such as the development new military equipment such as tanks or drones.