German and French foreign ministers raised proposals on Monday to prevent "erosion" of the European Union and improve its solidarity after Britain decided to leave the bloc in a referendum last week.
"We are seeing the European Union being severely put to the test," said German Foreign Minister Frank-Walter Steinmeier and French Foreign Minister Jean-Marc Ayrault in a joint document titled "A strong Europe in a world of uncertainties."
The two ministers said the decision of the British people last week marked a watershed moment in the history of Europe and created a new situation, reported Xinhua news agency.
"Neither a simple call for more Europe nor a phase of mere reflection can be an adequate answer," the document read, "To prevent the silent creeping erosion of our European project, we have to be more focused on essentials and on meeting the concrete expectations of our citizens."
Acknowledging that European Union (EU) member-states differ in their levels of ambition on European integration, Steinmeier and Ayrault said common answers must be found to address challenges faced by the EU.
The two core countries proposed to build a European Security Compact, a common European asylum and migration policy and to complete the Economic and Monetary Union.