A briefing by the United Nations' nuclear watchdog left U.S. senators "less assured" than before about the Iran nuclear deal, Senate Foreign Relations Committee chairman Bob Corker said August 5.
"The majority of members here left with far more questions than they had before the meeting took place," Corker said after a briefing on Capitol Hill lasting for more than an hour by International Atomic Energy Agency director general Yukiya Amano.
"It left me far less assured."
Amano had hoped to assuage concern in Congress, particularly about two confidential side deals the agency signed with Tehran that have drawn suspicions among legislators.
The agency is charged with monitoring Iran's nuclear activities under the deal. The Obama administration has described the side deals as "technical agreements" addressing access to Iranian nuclear sites and disclosing previous military dimensions of Iran's nuclear program.
Iran in July granted the agency tightly-controlled "managed access" to its military bases as part of the accord.
The agency's agreement was aimed in part at resolving suspicions about Iran's military facility at Parchin, where U.S. lawmakers, citing intelligence reports, say Tehran conducted past nuclear work.
Lawmakers have questioned what kind of access the agency would have to Parchin, but Amano was not able to satisfy their concerns.
"We can not get him to even confirm that we will have physical access inside of Parchin," Corker said.
Amano told reporters he understands their frustrations, but he said "my legal obligation is to protect safeguards confidentiality."
Should the agreement go into effect, he said, "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 agency's side deals with Iran.
"I thought today was helpful, but it was not a substitute for seeing the document," he said.
Senate Republican David Perdue 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 said. He described the deal 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 their details in a classified briefing with senators.
Senator Ted Cruz, a GOP presidential candidate, slammed the Iran accord after attending part of Sherman's briefing.
"This Obama-Iranian nuclear deal is a bad deal, and it keeps getting worse," he said.
Cruz said the details seen thus far "produce no comfort or security whatsoever."
"This deal is not materially different from simply calling the Iranian supreme leader, asking if they're developing nuclear weapons, and taking his word for it when he says no," he said.
Obama meanwhile nominated a senior White House adviser as the U.S. envoy to the UN agency.
Laura Holgate -- a special assistant responsible for weapons of mass destruction, terrorism and threat reduction -- was named to go to Vienna.