WASHINGTON — The Senate Foreign Relations Committee on Tuesday unanimously approved a measure that would establish a framework for Congress to examine and vote on a potential agreement with Iran over its nuclear program.

Following weeks of behind-the-scenes negotiations among senior committee leaders and staffers, the panel sent to the full Senate a measure setting up a 30-day review period of any deal with Iran. Further, it states Congress will put off votes on any deal under until after a June 30 deadline for Iran and six world powers to reach an agreement.

"I think this puts Congress in its rightful role," panel Chairman Bob Corker, R-Tenn., said of the legislation, which he crafted with Sen. Bob Menendez before the New Jersey Democrat was indicted on federal corruption charges earlier this month.

But the final negotiations were largely between Corker and the committee's new top Democrat, Sen. Ben Cardin of Maryland. Cardin lauded changes made to the bill in recent days, saying he believes the revised version is stronger than the initial one.

"We are clearing the way for a vote on the floor" should a final deal with Iran be brokered, he said.

Liberal and conservative committee members praised Corker and Cardin for working to craft something that members of both parties could support.

Sen. Marco Rubio, R-Fla., who on Monday entered the 2016 presidential race, and liberal Sen. Barbara Boxer, D-Calif., called the measure a "delicate balance." Boxer says she wants to "protect that." She also, however, said, however, she would fight to kill the bill should it be altered by Republicans, many of whom she said seem eager to "bomb Iran."

Class goat Alex Jordan Fletcher of Cosmopolis, Wash., graduating with the lowest grade point average, celebrates after receiving his diploma during a graduation and commissioning ceremony at the U.S. Military Academy on Saturday, May 21, 2016, in West Point, N.Y. (AP Photo/Mike Groll)
Class goat Alex Jordan Fletcher of Cosmopolis, Wash., graduating with the lowest grade point average, celebrates after receiving his diploma during a graduation and commissioning ceremony at the U.S. Military Academy on Saturday, May 21, 2016, in West Point, N.Y. (AP Photo/Mike Groll)

Sen. Chris Coons, D-Del., said the bill sends a message that the committee is reasserting that it has a "constructive and defined role to play" and also is signaling it will "stay engaged in oversight." He also said the measure would "help" American diplomats who continue efforts to strike a deal with Tehran.

A leading proponent of the bill, Virginia Democratic Sen. Tim Kaine, said "the American people overwhelmingly want Congress to approve a deal."

"Much better for us. Much better for the administration," Kaine said. "Much better for the P5+1. Much better for Iran, whom we're asking to make concessions."

Not all members were that enthused enthusiastic.

Sen. Ron Johnson, R-Wisc., repeated the GOP line that a nuclear deal with Iran would amount to "a treaty," and should include a mandatory up-or-down Senate vote. Still, Johnson said he would vote in favor of the Corker-Cardin version.

Rubio held fire on a controversial amendment that would have required Iran to formally recognize Israel. Many Democrats warned adoption of that measure could have killed the Corker-Cardin compromise. But he said the Senate eventually will have to debate the matter on the floor.

And Sen. Chris Murphy, D-Conn., warned the run-up to the committee's vote hints at "a double standard" under which Republicans conduct tougher oversight over diplomacy than war.

Shortly before the mark-up session began, the White House reversed course and signaled its support — after for months threatening President Barack Obama would veto the original version.

"If we arrived at a place where the bill that is passed by the Senate Foreign Relations Committee with bipartisan support essentially is a vote to vote later on congressional sanctions, and not ... about whether or not to enter into the agreement [with Iran]," White House Press Secretary Josh Earnest told reporters, "that would certainly resolve some of the concerns we've expressed about the authority that is exercised by the president of the United States to conduct foreign policy."

Corker said despite Earnest's comments, "this is exactly the congressional review process" that was contained in the initial version of the legislation.

Earlier Tuesday, both Coons and Sen. Susan Collins, R-Maine, told reporters that Obama administration officials had made it clear — including in a Tuesday morning briefing — that they opposed any vote on the Corker-Cardin legislation.

Class goat Alex Jordan Fletcher of Cosmopolis, Wash., graduating with the lowest grade point average, celebrates after receiving his diploma during a graduation and commissioning ceremony at the U.S. Military Academy on Saturday, May 21, 2016, in West Point, N.Y. (AP Photo/Mike Groll)
Class goat Alex Jordan Fletcher of Cosmopolis, Wash., graduating with the lowest grade point average, celebrates after receiving his diploma during a graduation and commissioning ceremony at the U.S. Military Academy on Saturday, May 21, 2016, in West Point, N.Y. (AP Photo/Mike Groll)

During the mark-up session, Corker said the White House had "relented" because they became resigned that the compromise version of the legislation likely would pass.

"They realized the number of senators who were going to vote for this bill," the chairman said.

On specifics, Corker said the review period "clock would only start" once the White House has submitted to Congress all of the documents related to an Iran pact.

A Corker aide explained the revised review period this way: "There is an initial review period of 30 days, 12 more days are automatically added if Congress passes a bill and sends it to the president, and an additional 10 days if the president vetoes the legislation. If the deal is submitted late, after July 9, the review period reverts to 60 days."

The change to a 30-day process was necessary to get the White House's support. Earnest told reporters that administration officials were concerned "carving out such a long window … could delay over a long period of time the implementation of the agreement."

One change that brought the White House's endorsement was the stripping of a provision inserted by Menendez tying the deal, the proposed congressional review and future votes to Iran's alleged support for terrorism.

Cardin broke with the man he replaced as ranking member, saying the terrorism provision should not be tied to a congressional review and possible vote on a deal over Iran's atomic program.

Menendez later said the change would not cause him to oppose the bill, saying he would continue to target Iran's alleged sponsorship of terrorist activities "in other venues."

The White House also had objected to any legislation that proposed congressional action on sanctions lawmakers did not put in place. Corker said at the start of the mark-up his bill only addresses Congress-enacted sanctions.

The bill also would require the president to "certify to Congress every 90 days that Iran is complying with the terms of the final agreement," a Corker aide said.

Corker also said his legislation would give Congress more data "than ever" on things like Iran's ballistic missile program. "than ever."

Many of the changes were included in a "manager's package," which also passed unanimously, 19-0.

The legislation would require President Barack Obama to submit to Congress, by the fifth day after reaching any deal with Tehran, the text of the pact. Obama also would have to submit a report that would be prepared by Secretary of State John Kerry assessing the ability to verify Iran's compliance.

Included in that "verification assessment report" would be a list of any sanctions the White House intends to waive, something opposed by that many Republicans oppose and that causes great skepticism among many Democrats. The bill would require a presidential certification that any deal would not allow Tehran to develop a nuclear weapon or "constitute an unreasonable risk to the common defense and security."

Coons said said the agreement brokered ahead of the mark-up would require a 60-vote threshold on the Senate floor to approve the Corker bill.

But should the president veto the bill, and should it also pass the House, the pact would require a 67-vote threshold to override Obama's veto.

Democratic senators stressed that lawmakers should avoid nixing any deal with Iran should such a vote eventually occur.

"The alternative to this," Boxer said of military strikes, "is frightening to the American people."

Twitter: @BennettJohnT