Secretary of State John Kerry admitted Tuesday that congressional disapproval of the nuclear deal with Iran would effectively kill the deal because Tehran would be unwilling to renegotiate it.

"Nothing works for them unless this deal is accepted," Kerry told the House Foreign Affairs Committee.

Lawmakers are expected to vote in mid-September whether to approve or disapprove of the deal reached July 14 in Vienna. Only a vote of disapproval that overcomes a promised presidential veto would affect the deal, by barring President Obama from waiving U.S. sanctions enacted into law.

Though the rest of the deal would remain, Kerry said enactment of a disapproval resolution by Congress would effectively kill it.

"It's physically impossible" for the deal to continue because of the bar to waiving U.S. sanctions, Kerry said.

"There's no way for the deal to work because our lifting of sanctions is critical to the ability of other countries to invest and work and critical obviously for Iran to get any money," he added.

Earlier, Kerry was asked by Rep. Brad Sherman, D-Calif., if he would obey the will of Congress if a disapproval resolution was enacted.

His response: "I can't begin to answer that at this point without consulting with the president."