Updated 1pm with Prime Minister's comments

The future of the EU hinges on Europe's ability to implement a social dimension, Prime Minister Joseph Muscat warned this morning in Rome.

In his speech, just before all member states signed the Rome Declaration, Dr Muscat warned that Europe was at a juncture where every turn will have consequences that will resonate for years to come. The solution, he insisted, was not to stay put.

Europe has changed and will continue to change. Rediscovering our values was not about being romantic, but rather about being ambitious for a better Europe, he said.

The Prime Minister also called for better gender and LGBTIQ equality in Europe.

Dr Muscat is in the Italian capital to celebrate 60 years since the founding fathers of the EU met in the same city to sign the Treaties of Rome.

Instead of uniting the continent using armed forces, the founding fathers chose the force of law, and on March 25, 1957, the Treaty of Rome established the European Economic Community. This led to the creation of the Single Market in 1993.

READ: Thousands march in London to protest against Brexit

But the recent rise of populism and anti-EU sentiment, which was reaffirmed by the Brexit referendum last year, has raised doubts across the board about the union's future.

Dr Muscat said: “We must do what we say, and we must say what we do. Doing nothing is not an option, unless we want to go down in history as the ones that dismantled a project which brought peace and prosperity to Europe.”

Joseph Muscat is greeted by Italy's PM Gentiloni as European Council President Tusk applauds.

In his address, Dr Muscat insisted solidarity was not a-la-carte, and reiterated that the principle of solidarity was enshrined in the treaties signed 60 years ago.

EU solidarity should go beyond migration.

He also referred to yesterday's appeal by Pope Francis, who noted that the treaties had given birth, primarily, to a human union.

“This is where our future lies: a human Union. Success of the union hinges on our ability to implement a social dimension,” he said.

Fielding questions during a press conference later, Dr Muscat said the EU would be moving forward in a way that respected the national identities and realities of member states.

“Six months ago, very few people would have bet one euro that there would be convergence, among 27 states, on moving forward on the social dimension.

“I think that this is something that can be delivered and I do believe that it is part of the antidote to rising populism,” the Prime Minister said.

We need to show we've learnt the lesson - Italian PM

Addressing the same audience, and referring to economic, migration and security issues, Italian Prime Minister Paolo Gentiloni, meanwhile noted that in some instances, Europe had turned up too late.

“We cannot stop when the entire world around us is moving on. Unfortunately, we stopped, and that triggered - in part through public opinion, but also within the majority in the UK - a crisis of rejection.”

It was now time to show that the union had learnt the lesson, and we do have the strength to start out again, he insisted.

Mr Gentiloni urged his colleagues to be brave enough to turn over a new leaf and move forward with enhanced cooperation. 

Europe needs to change, not destroyed - EP president

Ahead of the signing of the Rome Declaration, president of the European Parliament Antonio Tajani also referred to "mistakes" committed over the past years. The union, he said, was not complete.

We cannot start off again without bringing people closer, he added.

Today’s celebration could not be about rhetoric or a moment of complacency. Instead, the EU had to relaunch growth, attract investment, make Europe fairer and more attractive, he said.

During his address, he warned that no European state had the clout to negotiate on its own with the US, China and Russia.

He also referred to the London attack on Wednesday, noting that in order to be able to protect citizens, there was a need for more mutual trust and better exchange of intelligence.

"We need European unity as never before... Europe needed to be changed, not destroyed."

European Parliament President Tajani holds up a document signed by EU leaders.

'We're not proud enough of Europe's achievements'

The President of the European Council Donald Tusk, spoke about sovereignty, an issue that is often put in doubt by eurosceptics.

He insisted that only a united Europe can be a sovereign Europe, and only a sovereign Europe guaranteed freedom for its citizens.

Today, it was not enough to call for unity and protest against a multiple-speed Europe. It was much more important to respect common rules, such as freedom of speech, freedom of assembly and the rule of law, among others. 

President of the European Commission Jean-Claude Juncker meanwhile noted that Europeans were not “proud enough” of Europe’s achievements.

“When I travel to Africa and Asia, it feels as if the further away I go, the higher the approval of what is achieved in Europe… I think that people view Europe better the further away that they are.”

Mr Juncker reminded those present that following the agreement 60 years ago, peace had been given “a home on the European continent”.

Nowadays, none of the ranging conflicts in the world was on European territory, and we had to make sure that this remained the case.

Tight security in Rome

Security is tight in Rome today, with Italian media reporting that the Italian Civil Aviation Authority closed the airspace over the city yesterday. The ban reportedly includes flights by ultralight aircraft and drones.

Several roads around Campidoglio, where the heads of state are meeting, have been cordoned off, keeping out vehicles and pedestrians.

Wednesday’s London attack saw Italy increase security measures. Interior Minister Marco Minniti commented ahead of today’s celebrations: "we are faced with a threat that is taking on, ever more, the character of unpredictability: the times of reaction to the threat are being ever more reduced".

The centre of the Italian capital was already set to be in lockdown amid fears that a EuroStop march, expected to draw thousands of protestors, may be infiltrated by extremists.

Some six marches, including pro and anti-EU, are planned for today.