The nuclear agreement, which would lift sanctions on Iran in exchange for restrictions designed to prevent it from developing a nuclear weapon, would ultimately provide a financial windfall to Israel’s sworn enemy in the region, and Mr. Obama said he was prepared to hold “intensive discussions” with Mr. Netanyahu on what more could be done to bolster Israel’s defenses, administration officials said.

But, as in previous talks with Mr. Obama, Mr. Netanyahu refused to engage in such talk “at this juncture,” the officials said, speaking on the condition of anonymity to detail the private discussions. And on Tuesday, as administration officials fanned out to make the case for the Iran agreement, one aide suggested in a phone call to Jewish and pro-Israel groups that Mr. Netanyahu had rebuffed their overtures because he believes accepting them now would be tantamount to blessing the nuclear deal, say people involved in the call who did not want to be quoted by name in describing it…

Mr. Netanyahu “perhaps thinks he can further influence the congressional debate, and I’m confident we’re going to be able to uphold this deal and implement it without Congress preventing that,” Mr. Obama said in an interview with the New York Times columnist Thomas L. Friedman on Tuesday, hours after announcing the accord.