The President of the European Council, Donald Tusk, said Saturday it was not enough simply to call for unity but that EU countries also needed to put common values into practice, as EU leaders marked 60 years since the signing of the Treaty of Rome, which established the European Economic Community.

The leaders of 27 European Union countries, excluding the UK, posed for a family photograph in Rome after the commemorative ceremony and also signed a new Rome declaration, reaffirming their commitment to a united future. 

British Prime Minister Theresa May was absent from the event as Britain prepared to trigger the Brexit procedure next week.