US President Barack Obama signs a students presentation of Duke Ellington March 14, 2011, as he visits Kenmore Middle School in Arlington, Virginia. Obama on Monday issued a new pledge of support for Japan, saying he was “heartbroken” at the toll of “multiple disasters” after an earthquake and tsunami. Obama reiterated American support for the key US Pacific ally at the start of a speech on education at the school in the Washington suburbs. AFP PHOTO/Jim WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)

US President Barack Obama signs a students presentation of Duke Ellington March 14, 2011, as he visits Kenmore Middle School in Arlington, Virginia. Obama on Monday issued a new pledge of support for Japan, saying he was “heartbroken” at the toll of “multiple disasters” after an earthquake and tsunami. Obama reiterated American support for the key US Pacific ally at the start of a speech on education at the school in the Washington suburbs. AFP PHOTO/Jim WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)