French President Francois Hollande and U.S. President Barack Obama are both determined to obtain guarantees from Iran that it will not seek to develop a nuclear weapon, Hollande's office said on Wednesday. The United States, European Union and Iran worked for months on a proposal to end a 10-year stand-off over Tehran's nuclear program. Talks in Geneva last week between Iran and six world powers made notable progress towards a deal before snagging on some details, and will be resumed on November 20.