Obama challenges Russia to agree to deeper nuclear weapon cuts

German Chancellor Angela Merkel watches as U.S. President Barack Obama waves after giving a speech in front of the Brandenburg Gate in Berlin June 19, 2013. REUTERS/Michael Kappeler/Pool

BERLIN (Reuters) - U.S. President Barack Obama used a speech in Berlin on Wednesday to call on Russia to revive the push for a world without nuclear weapons, offering to cut deployed nuclear arsenals by a third, but Moscow immediately poured scorn on his proposal.

Speaking in Berlin where U.S. Presidents John F. Kennedy and Ronald Reagan gave rousing Cold-War speeches, Obama urged Russia to help build on the "New START" treaty that requires Moscow and Washington to cut stockpiles of deployed nuclear weapons to 1,550 each by 2018.