US president Barack Obama has echoed the famous "Ich bin ein Berliner" line by John F Kennedy with a speech at Berlin's iconic Brandenburg Gate in which he called on Russia to move beyond Cold War nuclear posturing and cut nuclear stockpiles.
After removing his jacket to keep cool in the heat, the president delivered a rousing speech to a cheering crowd in bright sunshine.
"We're now standing around the symbols of a Germany reborn," he said. "While I am not the first American president to come to this gate, I am proud to stand on its eastern side to pay tribute to its past," he said.
"No wall can stand against the yearnings for justice, the yearnings for freedom, the yearnings for peace that burns in the human heart."
He called for a reduction of nuclear arsenals and for new treaties to control the production of atomic weapons to reduce deployed nuclear weapons by up to a third. He urged Russia to drop its "Cold War postures".
His proposals come two years after the New Start (Strategic Arms Reductrion Treaty) deal between Moscow and Washington that set a limit on nuclear stockpiles of 1,550 warheads on each side by 2018. He also proposed preventing countries such as North Korea and Iran from getting nuclear weapons.
Moving on to Guantanamo Bay, he said his administration was "redoubling its efforts" to close it down.
Obama's speech took place almost exactly 50 years after President John F Kennedy delivered his "Ich bin ein Berliner" - or "I am a Berliner" - speech in the city that had been carved up between the West and the Soviet Union after the Second World War until the Berlin Wall came down in 1989.
"The greatest tribute that we can pay to those who came before is by carrying on their work to pursue peace and justice," he said.
"The wall belongs to history, but we have history to make as well. And the heroes that came before us now call to us to live up to our highest ideals."
Before ending with a quote from Martin Luther King - "Injustice anywhere is threat to justice everywhere" - Obama addressed briefly Eruopean concerns over internet privacy in the wake of the NSA surveillance scandal.
"[US must] balance security with privacy. I'm confident that the appropriate balance can be struck," he said.
He said surveillance kept people safe.
He had earlier told a press conference in Berlin's chancellery that US authorities were not "rifling through the emails" of ordinary people.
"I was a critic of the previous administration for those occasions in which I felt they had violated our values and I came in [to office] with a healthy scepticism about how our various programmes were structured," he said.
Obama's remarks on the NSA dominated the press conference, which also covered Syria, the global economic crisis and Guantánamo.
His remarks in Germany were particularly meaningful after some experts compared the NSA practices to those of the Stasi, the state intelligence arm operating during the communist dictatorship of East Germany.