President Barack Obama
President Barack ObamaReuters

President Barack Obama plans to tell the American people in an address on Wednesday that rejecting the nuclear agreement with Iran by Congress would be a "historic mistake," a senior White House official said, according to Haaretz.

Obama's remarks will be a response to Prime Minister Binyamin Netanyahu, who repeatedly called the deal with Iran historic mistake.

On Tuesday, 24 hours ahead of his planned speech, Obama met with some 20 prominent Jewish leaders and activists. The session lasted more than two hours during which Obama laid out the key points of his remarks and the reasons why he thinks they deal with Iran should receive their support, according to Haaretz

The White House said that Obama described the deal as historic, and emphasized to the Jewish leaders that it would prevent Iran from obtaining nuclear weapons. He also made it clear that the U.S. will continue to support and help strengthen Israel's security.

In his address on Wednesday, according to the White House official, Obama will stress the importance of the decision facing Congress, and label it as the most consequential debate in U.S. foreign policy since the decision to declare war on Iraq.

Obama "will make the case that this should not even be a close call – this deal has the most comprehensive inspections and transparency regime that we’ve ever negotiated," the senior official said.

The deal, added the official, "cuts off all of Iran’s pathways to a bomb, and includes a permanent prohibition on Iran obtaining a nuclear weapon."

The senior White House official noted that Obama will point out that the same people who oppose the nuclear deal with Iran now, supported going to war with Iraq. Obama will say that "it would be an historic mistake to squander this opportunity – removing constraints on the Iranian program, unraveling the sanctions regime, and damaging American credibility," he added.

Differences remain between Israel and the United States over the nuclear deal with Iran. Netanyahu on Tuesday held a live webcast with American Jewish leaders, in which he warned against the deal again.

Speaking in the webcast hosted by the Jewish Federations of North America and the Conference of Presidents, broadcast to 10,000 people, Netanyahu hit out at unnamed opponents who misrepresented the deal and Israel's stance against it.

"The more people know about the deal the more they oppose it," he added, arguing that the "most outrageous" lie was that those opposing the deal - including Israel - want war, and are against any form of diplomatic agreement. 

Such claims are "just not true," he said.

"The alternative is still no deal or a better deal - not war," he said. "The claim Israel wants war is not only wrong - it is outrageous."

He described that as "utterly false," saying that "we are the front lines." 

"This is not a partisan issue in Israel. It should not be a partisan issue in the United States."

Congress, meanwhile, continues to review the deal that was reached last month between Iran and six world powers and has until September 17 to accept or reject it.

Republicans have objected to the deal as not tough enough to prevent Iran obtaining a nuclear weapon in the long run, while several Democrats have expressed support.

Obama has threatened to veto any legislation passed by Congress blocking the deal, but Representative Peter Roskam (R-IL) said on Monday he was confident a new Congressional resolution calling to end the Iran nuclear deal would secure the support of two-thirds of lawmakers, thus rendering Obama unable to veto it.

Earlier on Tuesday, Representative Ed Royce (R-CA), Chairman of the House Foreign Affairs Committee, introduced legislation that would prevent the implementation of the Obama administration’s nuclear agreement with Iran.

“While a tremendous amount of effort was put into these negotiations, the result falls well short of this standard,” said Royce. “That’s the only conclusion I can come to after dozens of hearings with independent experts who have expressed extreme misgivings about this deal, especially the lifting of the arms embargo on Iran’s ICBM program.  The agreement gives Iran permanent sanctions relief, but in exchange only temporarily restrains Iran’s nuclear program.”