Republicans were left unconvinced after US Secretary of State John Kerry’s closed-door presentation to the Senate Banking Committee on Wednesday, which was aimed at delaying a new round of sanctions against Iran.

“It was an emotional appeal,” committee chairman Sen. Bob Corker said, according to the US-based media outlet BuzzFeed. “I have to tell you I was very disappointed in the presentation.”

He said that the briefings by Kerry, Vice President Joe Biden and Undersecretary of State for Political Affairs Wendy Sherman provided no details of a deal being considered in talks between the Islamic Republic and the P5+1 in Geneva this month.

“I am stunned that in a classified setting when you’re trying to talk to the very folks that would be originating legislation relative to sanctions, to have such a lack of specificity,” BuzzFeed reported Corker as saying.

Sen. Mark Kirk called the officials’ presentation “very unconvincing,” and added that it was “fairly anti-Israeli.”

“I was supposed to disbelieve everything the Israelis had just told me, and I think the Israelis probably have a pretty good intelligence service.”

The BuzzFeed report cited a Senate aide who said that “every time anybody would say anything about what would the Israelis say they’d get cut off and Kerry would say ‘you have to ignore what they’re telling you, stop listening to the Israelis on this.'”

Kerry warned the committee Wednesday against hurting a historic opportunity for a nuclear pact with Iran by pressing ahead with new sanctions while international negotiators seek to prevent Tehran from being able to assemble an atomic weapons arsenal.

Kerry said the United States and other world powers are united behind an offer they presented to Iranian negotiators in Geneva last week. But he said new action now from US lawmakers could shatter an international coalition made up of countries with interests as divergent as France, Russia and China, endangering hopes for a peaceful end to the decade-long nuclear standoff with the Islamic republic.

The countries worry that Tehran is trying to assemble an atomic weapons arsenal. Iran insists its program is solely for peaceful energy production and medical research.

“We put these sanctions in place in order to be able to put us in the strongest position possible to be able to negotiate. We now are negotiating,” Kerry told reporters ahead of testifying before the Senate Banking Committee. “And the risk is that if Congress were to unilaterally move to raise sanctions, it could break faith in those negotiations, and actually stop them and break them apart.”

With nuclear negotiations set to resume in Switzerland next week, the Obama administration dispatched Kerry and Biden to Congress on Wednesday to seek more time for diplomacy. They faced skepticism from members of Congress determined to further squeeze the Iranian economy and wary of yielding any ground to Iran in the talks.

Kerry said the negotiators should have a ‘few weeks’ more to see if they can reach an agreement.

The request faces sharp resistance from members of Congress determined to further squeeze the Iranian economy and wary of yielding any ground to Iran in the talks.

“The Iranian regime hasn’t paused its nuclear program,” said Rep. Ed Royce, a Republican and House Foreign Affairs Committee chairman. “Why should we pause our sanctions efforts as the administration is pressuring Congress to do?”

Kerry said the potential accord with Iran relates to a “tough proposal,” adding: “If it weren’t strong, why wouldn’t Iran have accepted it yet?”

Kerry said, “What we are asking everyone to do is calm down, look hard at what can be achieved and what the realities are. If this doesn’t work, we reserve the right to dial back the sanctions. I will be up here on the Hill asking for increased sanctions, and we always reserve the military option. So we lose absolutely nothing, except for getting in the way of diplomacy and letting it work.”

Last week’s talks broke down as Iran demanded formal recognition of what it calls its right to enrich uranium, and as France sought stricter limits on Iran’s ability to make nuclear fuel and on its heavy water reactor to produce plutonium, diplomats said.

The new sanctions were overwhelmingly approved by the Republican-led House in July. The legislation blacklisted Iran’s mining and construction sectors and committed the US to the goal of eliminating all Iranian oil exports worldwide by 2015. If the Senate Banking Committee pushes off its parallel bill any longer, lawmakers could attach it to a Senate defense bill which could come up for debate as early as Thursday.

In a rare public appearance on Wednesday, Hezbollah leader Hassan Nasrallah warned that if negotiations with Iran fall apart, it could ignite a war in the Middle East.

Prime Minister Benjamin Netanyahu “is doing everything he can to make the Iranian nuclear negotiations [in Geneva] with the P5+1 countries fail,” Nasrallah claimed.

The terror chief further accused the prime minister of “pushing for war” and of becoming a “spokesperson for several Arab countries” who are also “acting similarly to Israel and rejecting a political solution in Syria and any international accord with Iran.”

“Israel wants the US to attack Syria, Afghanistan and Iran to preserve its security,” he added.

“To all Arab peoples in the Gulf countries of Saudi Arabia, Kuwait, Qatar, Bahrain, UAE and Oman: What is the alternative to an understanding between Iran and world leaders? It is regional war,” Nasrallah warned.

But, he went on, “any accord that prevents a war in the region is rejected by Israel.”

An Israeli government official said Wednesday that Israel is not opposed to an interim deal with Iran if it entails the complete cessation of uranium enrichment.

“We’re not a priori opposed to an interim deal. I heard [Netanyahu] say that many times,” the official told The Times of Israel, insisting on anonymity. However, he added, in any such deal, Tehran would not be allowed to continue enriching any uranium, not even to a low degree, and would receive in return a suspension of further sanctions, while all existing sanctions would remain in place.

The Associated Press contributed to this report.