The European Council President called for the 27-nation superstate to introduce Permanent Structured Cooperation on Defence (PESCO) to protect the bloc from the effects of the migrant crisis, hostile bordering states and forces that risk tearing the bloc apart.
He added the EU should be prepared to spend huge amounts on the project, which will come with its own centralised headquarters and ambitious plans for EU military missions abroad.
Critics have repeatedly warned that the new system is a gateway to the creation of an EU army, although Brussels itself denies this and says it is just facilitating better military cooperation.
It goes hand in hand with plans for a centralised European Defence Fund, which is designed to help create an EU defence industry and reduce reliance on foreign powers like the US for military equipment.
Mr Tusk said: “We are a territorial community, which means that we have a common territory and common external borders.
“Our duty is to protect them.
“The migration crisis has made us aware, with full force, of the need to rebuild effective control of our external borders, while the aggressive behaviour of certain third countries, and the destabilisation around Europe, has made us aware of the need to defend our territory.
“For this reason we want to launch PESCO by the end of this year.
“In order to protect our external borders, we must build a model of durable and efficient financing on a bigger scale than ever before.”
Mr Tusk, one of the EU’s top three officials, went on to call on the Parliament to protect Europe’s “heritage”.
He added: “Secondly, We are a cultural community, which doesn’t mean that we are better or worse – we are simply different from the outside world.
“Our openness and tolerance cannot mean walking away from protecting our heritage.
“We have the right and obligation to care for what distinguishes us from other cultures – not in order to be against someone, but to be ourselves.
“Without a feeling of superiority, but with a feeling of justified pride.”
Last month the bloc’s foreign affairs chief Federica Mogherini insisted PESCO should be ready to go in time for January 2018, over a year before the UK is due to leave the union.
British ministers, including Boris Johnson and Michael Fallon, have been signing up to the EU’s military plans on the basis that they will lay down a loose marker for post-Brexit security cooperation.
However, the EU sees the commitments as legally binding, and respected military commander Major-General Julian Thompson has previously warned it will not be easy for the UK to “extricate” itself in the future.
He told express.co.uk: “The UK believes it is approving military structures for the other 27, but the EU is completely clear that agreements, unfortunately, apply to the UK as full participants.”