The next round of nuclear negotiations with Iran will be "pretty tough," a senior United States official told the Reuters news agency on Wednesday.
Iran and the six major powers reached a framework nuclear deal on April 2 in Lausanne, Switzerland, and are seeking to reach a final agreement by a June 30 deadline.
"As we expected after Lausanne, the next portion of this process will be pretty tough because we will be getting down to the details," the official told reporters as negotiators from prepared to converge on Vienna for a new round.
Among the key issues yet to be resolved between the sides are the sequencing of any sanctions relief for Iran as well as the monitoring and verification measures to ensure Iran is not secretly violating any agreement that might be reached.
The U.S. official said the sides were having “detailed discussions” about access to Iran’s military sites.
Iran has categorically denied reports that it would allow inspectors into its sites as part of a final deal, describing them as mere rumors and as wrong interpretations of the understanding reached in early April.
Iran’s Deputy Chief of Staff last week reiterated that the Islamic Republic will not allow any inspection of its military sites, calling the demand to do so “excessive”.
"We know there will not be an agreement until we can resolve that the IAEA will be able to verify whatever way is appropriate, whatever is necessary for this agreement, and that will include having managed access to a variety of sites and places in order to get this deal done," the official said, according to Reuters.
On Tuesday, the European Union said its political director, Helga Schmid, and negotiators Abbas Araqchi and Majid Takht-Ravanchi from Iran would meet in Vienna on Wednesday and would be joined later in the week by the other negotiators.
"Everyone in the room is focused on June 30. It doesn’t help any of us to delay difficult decisions," the U.S. official said.