BERLIN (AP) — President Barack Obama is challenging Americans and Europeans not to become complacent even though the Cold War is over.

Obama is speaking at Berlin's iconic Brandenburg Gate nearly 50 years after John F. Kennedy's famous speech in the once-divided city.

Obama says there's a temptation to turn inward now that barbed wire and concrete walls no longer separate East and West in Berlin. He says he's returned to Berlin because the tests of our time require the same fighting spirit. He's pointing to poverty and unemployment as ongoing challenges requiring the world's attention.

Obama says, quote, "Our work is not yet done."