U.S. Secretary of State John Kerry and his Iranian counterpart May 30 and 31 will launch a high-stakes diplomatic drive to nail down an unprecedented nuclear deal in only one month.
U.S. officials said they expect the weeks leading to a June 30 deadline to be "intense," and they vowed to "keep the pressure on" to force the Iranians to make the "tough decisions" needed to put a nuclear bomb beyond Iran's reach.
Kerry and Iranian Foreign Minister Mohammad Javad Zarif will meet in the Swiss city of Geneva, where they and western powers sealed the broad outlines of a deal in April.
"You'll see it escalate at the political level," a senior State Department official said, predicting an "intense month."
"Kerry will stress to Zarif the importance of granting access for inspections," a western diplomat said.
"It's one of the key legs of the stool. It's not the only leg, but if it is not included, then the stool will fall over."