“It's pretty evident that the sanctions piece – the momentum has changed,” he told the Washington Examiner Tuesday.
Corker was referring to a bill sponsored by Sens. Bob Menendez, D-N.J. and Mark Kirk, R-Ill., that would have allowed the diplomatic process to play out for a year before imposing new sanctions. In early January, the measure had attracted 59 co-sponsors - 14 of them Democrats - and Senate aides said they believed the bill would garner a veto-proof majority if allowed a vote on the chamber floor.
Since that time, the Obama administration has led a campaign to prevent the bill from reaching the floor, saying any new sanctions action in Congress would derail the interim six-month deal with Iran, which lifts some sanctions in return for freezing aspects of Tehran's nuclear program.
Corker has been pushing a potential compromise that would involve passing a bill that details what the Obama administration hopes to gain in a more comprehensive agreement with Iran. In recent weeks, however, he said he has found that the administration is dead-set against any congressional effort to define the final endgame with Tehran.
“The thing they have been far more concerned about is us laying out what the end deal has to look like,” he said Tuesday.
During a Senate Foreign Relations Committee hearing Tuesday, Menendez, the panel's chairman, expressed concern that the U.S. and five other world powers had jeopardized the solidarity of international sanctions without extracting long-term concessions from Iran.
“This is not a nothing-ventured, nothing-gained enterprise,” he said. “We have placed our incredibly effective international sanctions regime on the line without clearly defining the parameters of what we expect in a final agreement.”
Menendez also expressed concern that the head of Iran's nuclear agency last week on Iranian state television said “the iceberg of sanctions is melting while our centrifuges are also still working – this is our greatest achievement.”
After the hearing, Corker said there's a bipartisan group in the Senate worried that “we're going to have rolling interim deals and we're going to lose our sanctions” in the process.