Sen. Bob Corker, R-Tenn., is proposing a bipartisan compromise aimed at ending the Senate standoff over a new Iran sanctions bill and better clarifying what President Obama hopes to achieve in negotiations with Tehran over its nuclear program.

After a closed-door briefing with a select group of senators and Wendy Sherman, the undersecretary of State for political affairs, on Thursday, Corker said he suggested that the Senate pass a measure specifying the goals of the interim nuclear deal with Iran.

“One of the things people are generally concerned about — even those who support the administration — is they want, I want, to see a negotiated settlement. I'm just worried that the administration has started this with an interim agreement that is so milquetoast, I mean, it's almost as if Iran has to do nothing, okay?” Corker told the Washington Examiner.

Corker, the top Republican on the Senate Foreign Relations Committee, said a growing contingent of senators worry that the sanctions regime they helped build against Iran could “crater” as the talks proceed.

“I think there is some gelling, some creativity popped out in that meeting — that there are some ways that Congress might weigh in and even have a bigger impact than what we've been looking at [in the new sanctions bill],” he said an hour after the meeting ended. "A lot of conversations have taken place since the meeting."

One senior Congressional aide familiar with the Senate debate over the Iran deal said any compromise bill must give lawmakers the power to approve or reject the parameters of a long-term deal with Iran.

“If all your legislation does is say, 'Mr. President, here's what we'd like to see in a final deal,' but the resolution doesn't mandate any minimum standards and it doesn't require the final deal to be subject to Congressional approval, you've basically given Barack Obama the power to cut a very bad deal with Iran that leads to nuclear weapons and war,” the aide said.

The aide also accused the Obama administration of trying to expand the president's executive authority to wrest away Congress' sanctions power.

“We know the president is currently looking for ways to circumvent the U.S. law and lift statutory sanctions unilaterally without congressional action – are Republicans really going to let him do that without a fight?” the aide asked.

Sherman, the administration's lead negotiator in the Iran talks, spent an hour on Capitol Hill on Thursday evening speaking privately to a small bipartisan group of influential senators, including key committee chairmen and their ranking Republicans counterparts.

The Obama administration is pressing the Senate not to pass any new sanctions measures, arguing that it would derail the preliminary six-month deal with Iran to roll back parts of its nuclear program in exchange for nearly $7 billion in sanctions relief.

A new sanctions bill, sponsored by Sens. Bob Menendez, a New Jersey Democrat who chairs the Foreign Relations Committee, and Mark Kirk, R-Ill., has gained 59 co-sponsors in recent weeks but is currently stalled pending a vote scheduled by Senate Majority Leader Harry Reid, D-Nev.

Reacting to the possibility of a compromise bill, Kirk continued to push for a vote on legislation he authored with Menendez that would give the administration a year to continue its diplomatic negotiations with Iran before imposing tougher new sanctions.

“With support from the overwhelming majority of the Senate and the American people, Senator Kirk believes it's time to vote on the Nuclear Weapon Free Iran Act,” a spokesperson said. “The senator welcomes the opportunity to find common ground with the administration, but he believes the Senate must act now to protect the American people from Iranian deception and ensure Iran peacefully dismantles its illicit nuclear infrastructure in any final agreement.”

Emerging from the briefing, Sen. Lindsey Graham, R-S.C., a chief critic of the administration's six-month Iran nuclear deal, said he is “more disturbed than ever after the briefing.”

“The end game being contemplated is not even in the ballpark of what I would consider an end game,” he said.

Sen. Jim Inhofe, R-Okla., said nothing Sherman shared changed his mind about the sanctions bill and argued that the administration has yet to outline its exact goals in the negotiations with Iran.

But Sen. Carl Levin, a Michigan Democrat who chairs the Armed Services Committee, said he thought the meeting was “very persuasive” and only served to underscore his belief that passing a new sanctions bill could undermine the talks with Iran.

Levin handed reporters copies of a letter from Director of National Intelligence James Clapper that the committee received in December concluding that a new sanctions bill would unravel the negotiations with Iran.

“We judge that new sanctions would undermine the prospects for a successful comprehensive nuclear agreement with Iran,” Clapper said in the letter. “Iranian Foreign Minister Mohammad Javad Zarif in early December said that the entire deal would be 'dead' if the international community imposed new sanctions.”

This story was published at 9:43 a.m. and has been updated.