Japan ? Hiroshima’s mayor urged global leaders today to back President Barack Obama’s call to abolish nuclear weapons as Japan marked the 64th anniversary of the world’s first atomic bomb attack.

In April, Obama said that the United States — the only nation that has deployed atomic bombs in combat — has a “moral responsibility” to act and declared his goal to rid the world of the weapons.

At a solemn ceremony to commemorate the victims of the Aug. 6, 1945, attack, Hiroshima’s Mayor Tadatoshi Akiba welcomed that commitment.

“We refer to ourselves, the great global majority, as the ‘Obamajority,’ and we call on the rest of the world to join forces with us to eliminate all nuclear weapons by 2020,” Akiba told a crowd of thousands. The bombed-out dome of the building preserved as the Hiroshima Peace Memorial loomed in the background, and hundreds of white doves were released into the air as he finished speaking.