German President Frank-Walter Steinmeier warned against the dangers of nationalism Monday, as he visited a World War II massacre site in France a day after European elections saw advances for the far right.

It is "fittingly on the day after the European elections that I say: let us never forget the damage done in Europe by nationalism and hate. Let us never forget the miracle of reconciliation the European Union has worked," Steinmeier said at a commemoration ceremony for the village of Oradour-sur-Glane, where Nazi SS soldiers massacred civilians in 1944.

Among the German head of state's audience was President Emmanuel Macron, who called new national elections to France's parliament Sunday, after his party's disastrous showing in the European vote.

While Macron hopes to break the deadlock of a hung parliament that has dogged his second term since 2022, the far-right National Rally (RN) looks set to make significant gains from its current 88 lawmakers.

"It is in this memory, in the ashes of Oradour, that we have to ensure the strength of this reconciliation is reborn," Macron said, calling post-war Franco-German ties "the lifeblood of our European project".