President Obama spoke by phone Friday with Iranian President Hassan Rouhani, the first contact between the two countries’ leaders in over three decades, a historic conversation the White House is billing as the foundation for a deal on Tehran’s nuclear program.

Obama, who famously vowed in 2007 that he would pursue discussions with Iran, championed the 15-minute phone call with his Iranian counterpart while trying to mollify concerns from lawmakers and U.S. ally Israel.