German Chancellor Angela Merkel, U.S. President Barack Obama and Berlin Mayor Klaus Wowereit (L) leave after delivering their speeches at the Brandenburg Gate in Berlin, June 19, 2013. U.S. President Barack Obama will unveil plans for a sharp reduction in nuclear warheads in a landmark speech at the Brandenburg Gate on Wednesday that comes 50 years after John F. Kennedy declared "Ich bin ein Berliner" in a defiant Cold War address. REUTERS/Tobias Schwarz (GERMANY - Tags: POLITICS)