On a visit to fellow EU member Croatia, German President Frank-Walter Steinmeier said he is convinced that Europe needed to "speak with one voice" to still be relevant internationally.
In a jibe at recent nationalist tendencies across Europe, he said that "a withdrawal into the national shell that some are dreaming of cannot be the answer to Europe's past."
"Nor is it the way to shape our shared future," he emphasized at a reception with Croatian President Kolinda Grabar-Kitarovic. Germany, like other nations, is "just a small country in tomorrow's world."
He urged people to vote in EU elections from May 23-26 to "renew the promise of Europe."
Steinmeier is on a three-day trip to Croatia that ends on Friday. Both Germany and Croatia will hold the six-month rotating EU presidency in 2020.