WASHINGTON — Bowing to pressure from Republicans and his own party, President Barack Obama on Tuesday relented to a compromise empowering Congress to reject his emerging nuclear pact with Iran.
The rare and reluctant agreement between the president and the Republican-led Congress came after the White House maintained for weeks that congressional interference could jeopardize sensitive negotiations with Tehran. But lawmakers refused to back down from their insistence that Congress have a formal role in what could be a historic deal to prevent Iran from developing nuclear weapons.
The Senate Foreign Relations Committee unanimously approved the compromise bill shortly after White House spokesman Josh Earnest conveyed the president's decision to sign it.
"Maybe they saw the handwriting on the wall," House Speaker John Boehner, R-Ohio, said after the White House dropped its opposition.
Both houses of Congress are now likely to pass the bill, which cleared the committee 19-0. It's expected to come before the full Senate as soon as next week.
A vote on an actual agreement to lift economic sanctions in exchange for Iranian nuclear concessions would come later, if negotiations between the Obama administration, Iran and five other nations come to fruition.
Obama retains his right to veto any attempt by Congress to scuttle such a pact if the time comes. To override a veto would require a two-thirds majority of both the House and Senate, meaning some Democrats would have to oppose their president to sink a deal.
The White House's announcement came after an intensive administration effort to prevent Democrats from signing on to legislation requiring Obama to submit any pact with Iran to Congress.
International negotiators are trying to reach a deal blocking Iran's path toward nuclear weapons in exchange for relief from economic sanctions that are crippling its economy.
"We believe it is our role to ensure that any deal with Iran makes them accountable, is transparent and is enforceable," said Sen. Bob Corker, R-Tenn., chairman of Foreign Relations Committee.
Corker said Secretary of State John Kerry was lobbying against the legislation on Capitol Hill a few hours before the vote. The Republican said the White House's sudden support was dictated by the number of senators — Republicans and Democrats — backing the measure.
"I supported today's compromise after the administration assured me that the reworked bill would preserve our negotiators' ability to do their jobs," said Sen. Chris Murphy, D-Conn.
Obama, whose foreign policy legacy would be burnished by a deal with Iran, has been in a standoff for months with lawmakers who said Congress should have a chance to weigh in and remain skeptical that Iran will honor an agreement.
The United States, Britain, France, Germany, Russia and China reached a preliminary agreement with Iran on April 2 to curb its nuclear program and hope to finalize a pact by June 30.
Earnest said the White House would withhold final judgment on the bill while it works its way through Congress, wary that potential changes could be made in committee that would render it unpalatable. But he said the White House could support the compromise in its current form.
"Despite the things about it that we don't like, enough substantial changes have been made that the president would be willing to sign it," Earnest said.
An earlier version of the bill sought to put any plan by Obama to lift sanctions on Iran on hold for up to 60 days while Congress reviewed the deal. The compromise approved by the committee shortened the review period to 30 days. During that time, Obama would be able to lift sanctions imposed through presidential action, but would be blocked from easing sanctions levied by Congress.
Under the terms of the bill, if a nuclear deal is submitted after July 9 — a short time after the final agreement is to be reached — the review period would revert to 60 days. The president would be required to certify to Congress every 90 days that Iran is complying with terms of the agreement.
The compromise also struck a provision in the initial bill that would have required the president to certify that Iran is not supporting terrorism and substituted weaker language.
The original provision's author, Sen. John Barrasso, R-Wyo., tried Tuesday to add the requirement back in. But Corker and others said the amendment would be a deal-killer, and the panel rejected it.
Other GOP senators backed off their anti-Iran amendments.
Sen. Marco Rubio, R-Fla., who announced his candidacy for president on Monday, had proposed an amendment that would require Iran's leaders to accept Israel's right to exist. Rubio said his amendment probably could have passed in the committee, but ultimately "could imperil the entire arrangement."
Rubio said the new version has language on Israel that "is better than not having it at all" and that his original amendment might still come up during a debate by the full Senate.
Sen. Chris Coons, D-Del., said he felt confident that the compromises will hold, but said Democrats would withdraw their support if Republicans successfully push amendments that would pull the bill "sharply to the right." He was referring to amendments proposed by Republicans to make the administration certify that Iran is not supporting terrorism and had publicly renounced its threat to destroy Israel — two obstacles that would be nearly impossible to scale.
Sen. Barbara Boxer, D-Calif., said she opposed the bill in its original form, but now supports it.
"There's no longer language in the bill tying extraneous issues to the agreement," Boxer said. "That would be a deal breaker."
Associated Press writers Charles Babington, Josh Lederman and Alan Fram contributed to this report.