The Associated Press has learned that the United States and Iran secretly engaged in high-level, face-to-face talks at least three times over the past year.
The high-stakes diplomatic gamble by the Obama administration paved the way for the historic deal sealed early Sunday in Geneva aimed at slowing Tehran's nuclear program.
The discussions were kept hidden even from America's closest friends, including its negotiating partners and Israel, until two months ago.
Senior Obama administration officials confirmed to the AP details of the extensive outreach. The officials spoke only on the condition of anonymity because they were not authorized to discuss by name the highly sensitive diplomatic effort.
Iran foreign minister Javad Zarif has denied any secret engagement between two sides.