Former U.S. President Barack Obama urged people to unite against "nationalism and intolerance", arguing that amid greater global pressures, now is not the time to "hide behind a wall."
In his first public address since leaving the White House, Obama advocated the virtues of democracy and collaboration to an audience of tens of thousands in Berlin, Germany.
"In this new world that we live in we can't isolate ourselves, we can't hide behind a wall," he said during a celebration to mark the 500th anniversary of the Protestant Reformation.
The former world leader was joined by his German counterpart Chancellor Angela Merkel as they sat on a stage in front of the Brandenburg Gate and took questions from a panel, including a social worker, an actor and a teacher.
In a clear nod to rising nationalist sentiment across the U.S. and the EU, Obama said that globalization is not the enemy but should be embraced in order to fend off anti-democratic values.
"What we now have to recognize, because of globalization and because of technology, and the disruptions that have occurred … is that this (new world) order that has been created has to be updated and continually renewed, because there is a competing narrative of fear and xenophobia and nationalism and intolerance and anti-democratic trends."
He urged listeners to "rally against those trends that would violate human rights or suppress democracy."
"That is going to be a significant battle we have to fight," he said, just days after the U.K. was hit by the latest in a string of extreme Islamist attacks.