An 84-year-old atomic bomb survivor called on U.S. President Barack Obama to make further efforts to abolish nuclear weapons in a letter she handed to a close aide of the president during a meeting Monday in Washington.

"I wrote, 'We must act for the future of children' at the top of the letter," Setsuko Thurlow told reporters after meeting with Deputy National Security Adviser Ben Rhodes.

Thurlow, who moved to Canada after marrying a Canadian, was 13 when the U.S. atomic bomb hit Hiroshima in the final stages of World War II. An anti-nuclear activist, she said she also expressed her opinions about U.S. nuclear policies in the letter.