Rep. Steve Israel (D-Huntington), on May 1, 2014, in Washington,...

Rep. Steve Israel (D-Huntington), on May 1, 2014, in Washington, D.C. He said he is "highly skeptical" about a deal with Iran. Credit: AP / Evan Vucci

WASHINGTON -- President Barack Obama heralded a framework nuclear understanding with Iran as a "historic" agreement and warned Congress Thursday against taking action that could upend work toward a final deal.

"The issues at stake here are bigger than politics," Obama said during remarks in the White House Rose Garden. "These are matters of war and peace, and they should be evaluated based on the facts."

But skepticism quickly surfaced on both sides of the political aisle.

"I've been skeptical about a deal with Iran," said Rep. Steve Israel (D-Huntington). "The details deserve and must get a vote by the U.S. Congress. Until the full details are provided to Congress on June 30th, you can keep me in the 'highly skeptical' column."

On the Republican side, House Speaker John Boehner said it would be "naive to suggest the Iranian regime will not continue to use its nuclear program, and any economic relief, to further destabilize the region." Senate Foreign Relations Committee chairman Bob Corker (R-Tenn.) said his panel would vote this month on legislation giving Congress the right to approve or reject a final deal.

Obama called the agreement "a good deal, a deal that meets our core objectives." He said verification mechanisms built into the framework agreed to in Switzerland hours earlier would ensure that "if Iran cheats, the world will know it."

One of Obama's toughest challenges will be convincing lawmakers to hold off on legislation that would authorize new sanctions on Iran. He warned anew that approving new sanctions in the midst of the delicate diplomacy could scuttle the talks. "If Congress kills this deal, not based on expert analysis, and without offering any reasonable alternative, then it's the United States that will be blamed for the failure of diplomacy," Obama said.

Sen. Mark Kirk (R-Ill.), co-sponsor of a bill to impose new sanctions on Iran, said the agreement would leave Tehran with "vast capabilities" to produce nuclear weapons. "Neville Chamberlain got a better deal from Adolf Hitler," he said in a statement.

In his remarks, Obama called a prospective final agreement the best possible path to prevent Iran from acquiring a nuclear weapon. The president said that sanctions placed on Iran "for its support of terrorism, its human rights abuses, its ballistic missile program" will remain in place.

New York's two senators, both Democrats, were noncommittal as the negotiations with Iran move to their next phase.

The "announcement deserves careful, rigorous and deliberate analysis," Sen. Charles Schumer said in a statement.

Sen. Kirsten Gillibrand said, "While I am encouraged that progress has been made, and a framework for a deal is now in place, there are many details still left to be worked out and I look forward to a full briefing from the White House before passing judgment on the deal."

Rep. Lee Zeldin (R-Shirley) said, "A bad deal with Iran is worse than no deal at all. Today, America and our allies have been set backwards in the noble quest to secure the free world."

Rep. Peter King (R-Seaford) said, "I am concerned about the agreement locking in Iran's nuclear infrastructure. It is vital to see how real the inspection provisions are. In addition, I am concerned that Saudi Arabia, Egypt, Turkey and Qatar could start a nuclear arms race."

Rep. Kathleen Rice (D-Garden City) said, "This preliminary framework shows signs of progress and deserves real analysis and discussion, but there are still a lot of 'ifs' and uncertainties."

With Tom Brune

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