Senate Foreign Relations Committee chairman Bob Corker said lawmakers left today's briefing by the head of the UN nuclear watchdog agency "less assured" about the nuclear deal with Iran.
"The majority of members here left with far more questions than they had before the meeting took place. I can say from my perspective that it left me far less assured," Corker told reporters after an hour-plus briefing by International Atomic Energy Agency director general Yukiya Amano.
Amano travelled to Capitol Hill in a bid to assuage growing concern in Congress, where lawmakers will be voting in September on whether to approve the nuclear accord between Iran and world powers.
Washington has described the side deals as "technical agreements," which are believed to include a deal about Iran's documentation of the alleged "previous military dimension (PMD)" of its nuclear program.
Iran in July granted the IAEA tightly-controlled "managed access" to its military bases as part of the accord.
The IAEA agreement is aimed in part at resolving suspicions about Iran's military facility at Parchin, where US lawmakers, citing intelligence reports, say Tehran conducted past nuclear work.
Lawmakers have aired concerns about Iran's military capacity, and in particular what kind of access the IAEA would have to Parchin.
"We can not get him to even confirm that we will have physical access inside of Parchin," Corker said of Amano.
The IAEA chief told reporters he recognized the frustrations, but said he "explained that my legal obligation is to protect safeguards confidentiality."
Should Congress approve the joint comprehensive plan of action and it goes into effect, Amano stressed, "the nuclear activities of Iran will be reduced in size, and we'll have the most robust verification regime in Iran."
The top Democrat on the panel, Senator Ben Cardin, said it was important for members of Congress to at least be able to see key portions of the IAEA-Iran agreements.
"I thought today was helpful, but it was not a substitute for seeing the document. I think there's previsions in the document that relate to the integrity of the review of the PMD that would be useful," Cardin told reporters.
Senate Republican David Perdue, a member of the committee, emerged frustrated at Amano's lack of detail.
"The number one question we had was, are we going to get access to the two side agreements, and the answer was 'no'," Perdue told AFP, describing the nuclear deal with Iran as "troubling."
Meanwhile Wendy Sherman, undersecretary of state for political affairs, testified to the Senate Banking Committee that she has read the side agreements and would share key details of them later today in a classified briefing to senators.
