New York Times: “With a deadline approaching, Mr. Kerry thought the opportunity could be lost unless the Iranians finally offered a breakthrough compromise. But Mohammad Javad Zarif, the Iranian foreign minister, came with little new. Frustrated, Mr. Kerry said there was no way the United States would accept a deal that did not curb Iran’s ability to produce enough fuel for a bomb within a year. The conversation grew heated. The two men, patricians in their own cultures and unaccustomed to shouting, found themselves in the kind of confrontation they had avoided during multiple negotiating sessions over the past year.”

Said one American official: “This was the first time there were raised voices and some unpleasant exchanges.”