WASHINGTON >> Having beaten back a congressional campaign to derail his nuclear agreement with Iran, President Barack Obama now faces a panoply of challenges that may be just as daunting: making the deal actually work while repairing relations with disaffected allies and constraining Tehran’s regional ambitions.

He got started Friday even as the House was still voting by announcing that he would host Prime Minister Benjamin Netanyahu of Israel at the White House in November. The session will offer an opportunity for the estranged leaders to clear the air after a bitter and starkly partisan debate over the merits of the Iran deal and the depth of American commitment to Israeli security.

The president will use the meeting to renew a longstanding offer of more military aid to bolster Israel’s defenses as Iran receives tens of billions of dollars in sanctions relief from the nuclear accord — money that the prime minister has argued will go directly to funding terrorism against his country. Until now, Netanyahu has refused to talk about strengthened security cooperation to avoid looking as if he was accepting the Iran deal.

But supporters and critics alike said Obama must go much further by detailing how the United States and other world powers intended to enforce and monitor the nuclear agreement as Iran begins to dismantle centrifuges and open facilities to inspectors. And they said he needed to craft a comprehensive approach to countering Iran’s support for terrorist and rebel groups in the Middle East.

"The deal has to now be embedded in a larger Iran strategy and that is key to re-engaging and reinvigorating with allies and partners in the region," said Michele A. Flournoy, a former undersecretary of defense for Obama and now chief executive of the Center for a New American Security in Washington.

The message from Obama, she added, should be "OK, the nuclear piece, whether you were thrilled about it or not, is in place, but how are we going to work together to counter and deter Iran’s other activities in the region and its support for terrorism, and how are we going to reassure you with respect to your security?"

Obama on Friday tried to move past the heated congressional battle that climaxed with Thursday’s Senate vote in which opponents of the deal won a majority, but not enough to overcome a filibuster. House Republicans, joined by 25 Democrats, voted down a measure to approve the deal Friday, but the vote was purely symbolic because the president can move ahead with its terms on his own.

Republican critics in Congress plan to advance other measures to try to limit his ability to lift sanctions as part of the agreement, but they face an uphill climb in the Senate, where they do not seem to have enough votes to override an Obama veto.

Still, Republican presidential candidates on the campaign trail will keep the issue alive as they pound away against a deal they call dangerous and naive. And Democrats who voted for the deal while expressing deep reservations may be looking for a way to take actions countering Iran.

"The issue is still out there," said Dennis Ross, a former Middle East adviser to Obama and other presidents who is now at the Washington Institute for Near East Policy. "The concerns they have about Iran are still out there, and so you look for ways to address those concerns."

In a written statement on Friday, Obama thanked those Democrats who stood with him and pointed to the tasks ahead.

"Now we must turn to the critical work of implementing and verifying this deal so that Iran cannot pursue a nuclear weapon," he said. "In doing so, we’ll write the latest chapter of American leadership in the pursuit of a safer, more hopeful world."

The agreement will be formally adopted on Oct. 19 and in the months to come Iran must begin to disassemble; store more than 13,000 centrifuges and reduce its stockpile of low-enriched uranium by 98 percent; convert its underground Fordo enrichment facility to a research center; and disable the core of its heavy water reactor at Arak. Once initial steps are complete, the United States and Europe will begin to lift sanctions and begin granting Iran access to frozen funds.

Gary Samore, a former arms control adviser to Obama, said Iran had a strong incentive to carry out the necessary steps in the next few months, but it could be complicated by internal politics. With parliamentary elections set for February, he said, President Hassan Rouhani has an incentive to work fast to show benefits from the agreement, while hard-liners may want to drag out the process so he cannot claim credit.

Moreover, Samore said, there are already signs that Iran is supporting Hezbollah as it sets up a new position in southern Syria from which Israel fears new rocket attacks. The president, he said, needs to find a way to counter such actions.

"There are things we can do in the next few months to demonstrate that Iran’s ability to exploit the nuclear deal to expand its influence is very limited," said Samore, who is now at the Belfer Center for Science and International Affairs at Harvard University.

Mark Wallace, a former Bush administration diplomat who is now chief executive of United Against Nuclear Iran, an advocacy group that opposed the nuclear deal, said Obama should still discourage American companies from rushing into Iran just because some sanctions are to be lifted.

"The United States and its allies need to send a message that just because we’re lifting sanctions in the nuclear area does not mean that Iran is open for business," he said.

Without waiting for Congress, Obama has already begun working to bolster the security of Persian Gulf allies that were leery of the deal, including Saudi Arabia, whose King Salman met with Obama here last week. But less clear is the future of the relationship between Obama and Netanyahu, which was never close and then ruptured into acrimony this year over the Iran agreement.

Josh Earnest, the White House press secretary, said Obama hoped to restart conversations on more security assistance for Israel.

"The president has indicated on a number of occasions his desire to begin consultations with our Israeli allies about how to further deepen that cooperation," he said. "We’re looking forward to doing that."

Samore said Netanyahu may still not accept defeat and continue to work with Republicans to undermine the deal. On the other hand, he said, the Israeli prime minister may decide to extract the most he can out of Obama in his last 16 months in office.

"They’re never going to embrace and be good friends," Samore said. "That’ll never happen. But the implication is they’ll at least try to achieve an agreement" on security cooperation "or at least find enough common ground to make sure it isn’t a contentious meeting."

© 2015 The New York Times Company