The US State Department rejected over the weekend Israel’s demand that any final deal with Iran on its nuclear program include recognition of Israel’s right to exist, saying that was not the issue at hand.

“This is an agreement that is only about the nuclear issue,” State Department spokeswoman Marie Harf told reporters on Friday night, according to Fox News. “This is an agreement that doesn’t deal with any other issues, nor should it.”

Meanwhile the New York Times reported that the White House was already making intense efforts to sell the emerging deal to a reluctant Congress, in order to prevent legislators from blocking the accord.

Since the deal was announced on Thursday senior members of President Barack Obama’s staff, including Vice President Joe Biden, Chief of Staff Denis McDonough and National Security Adviser Susan Rice, have been phoning their colleagues in the House and the Senate as well as Jewish lobbying groups to convince them of the agreement’s merits, the Times reported.

Prime Minister Benjamin Netanyahu speaks out against a nuclear agreement between Iran and world powers, April 03, 2015. (Photo credit: Kobi Gideon/GPO)

A bipartisan bill being advanced in the Senate, the Iran Nuclear Agreement Review Act of 2015, would require any final agreement with Iran to be submitted to Congress for a 60-day review period before congressionally mandated sanctions on Iran could be waived or suspended by the president. Chiefly supported by Republicans, the bill has also gained some key backing from some Democratic lawmakers.

Obama has promised to veto the bill, saying it could wreck the nuclear accord and isolate the US in an intransigent position. The bill’s success or failure rests, therefore, on Republicans’ ability to sway Democrats to their camp in order to secure a veto-proof majority.

“The president has a big job here, and it’s going to be tough,” Senator Jeff Flake (R., Arizona), a member of the Foreign Relations Committee, told the Times. “Obviously, Congress knows that it has an important role to play, and the administration is reluctant to concede that.”

But the White House is hopeful that the agreement will be an easier sell now that its details are available.

“People were understandably skeptical because we did not have a deal to point to, but now that we do, it has strengthened our hand in dealing with Congress,” White House press secretary Josh Earnest said. “As they take a look at the agreement and the level of detail there is, it strengthens our case that not only are we achieving the aims we set out to achieve, but that we have a way of verifying it.”

Following the announcement by Iran and six world powers that they had reached a framework for a final nuclear deal, to be finalized by June 30, Prime Minister Benjamin Netanyahu said he and his government were united in “strongly opposing” the agreement.

Netanyahu said after a cabinet session Friday that “Israel will not accept an agreement which allows a country that vows to annihilate us to develop nuclear weapons, period.”

However, he also acknowledged the possibility of a final agreement being reached, and said that such a deal must “include a clear and unambiguous Iranian recognition of Israel’s right to exist.”

The White House expressed confidence on Friday night that a final nuclear agreement would be attained in the coming months.

“We feel good,” White House spokesman Eric Schultz said, according to Reuters. “There’s a lot of work to be done, but we are confident we can get those details in place.”

Netanyahu has harshly criticized the negotiations, demanding instead that the Iranian program be dismantled. He claims Iran cannot be trusted, and that leaving certain facilities intact would allow the Iranians to eventually build a bomb.

However, it appears unlikely Israel will be able to prevent the final deal amid broad international support for such an agreement.

China said Saturday that the framework agreement struck with Iran would also bolster Beijing’s relations with Washington.

According to a statement by the Chinese government quoted by Reuters, Foreign Minister Wang Yi spoke with US Secretary of State John Kerry about the deal and its effects in a phone call.

“China and the United States, both taking on major responsibilities in safeguarding the international nuclear non-proliferation system, maintained good contact with each other during the negotiations, while instilling positive energy into bilateral relations,” Wang told Kerry.

“In a bid to finalize a comprehensive deal as scheduled, China will maintain close coordination with all parties concerned, including the United States, and continue to play a constructive role during the process.”

German Foreign Minister Frank Walter Steinmeier on Friday sought to assure Israeli leaders concerned about the deal that it would improve Israel’s security.

German Foreign Minister Frank-Walter Steinmeier speaks while meeting with Secretary of State John Kerry at the State Department in Washington, Wednesday, March 11, 2015. (photo credit: AP Photo/Molly Riley)

“We ask the Israeli government to look more closely at the agreement,” Steinmeier said, according to Reuters. “Its main points are intended to guarantee that security in the Middle East…will improve, and not get worse.”

The German diplomat warned however that it was too early in the process to celebrate.

“We can be satisfied, but I hope equally that we can expect that Iran will stick to the main agreements,” he said.

The commitments announced Thursday, if implemented, would substantially pare back some Iranian nuclear assets for a decade and restrict others for an additional five years. According to a US document listing those commitments, Tehran is ready to reduce its number of centrifuges, the machines that can spin uranium gas to levels used in nuclear warheads.

Of the nearly 20,000 centrifuges Iran now has installed or running at its main enrichment site, the country would be allowed to operate just over 5,000. Much of its enriched stockpiles would be neutralized. A planned reactor would be reconstructed so it can’t produce weapons-grade plutonium. Monitoring and inspections by the UN nuclear agency would be enhanced.

Netanyahu has voiced concerns that the emerging deal would leave much of Iran’s nuclear infrastructure intact.

“They would not shut down a single nuclear facility in Iran, would not destroy a single centrifuge in Iran and will not stop research and development on Iran’s advanced centrifuges,” he said. “On the contrary. The deal would legitimize Iran’s illegal nuclear program. It would leave Iran with a vast nuclear infrastructure. A vast nuclear infrastructure remains in place.”

He called on the world powers to stand firm and increase pressure in Iran until what he termed a good deal is achieved.

Obama phoned Netanyahu hours after the framework was struck on Thursday, and the two men had what was reported as a difficult conversation.

“A deal based on this framework would threaten the survival of Israel. Just two days ago, Iran said that “the destruction of Israel is nonnegotiable,” and in these fateful days Iran is accelerating the arming of its terror proxies to attack Israel. This deal would legitimize Iran’s nuclear program, bolster Iran’s economy, and increase Iran’s aggression and terror throughout the Middle East and beyond,” Netanyahu told Obama during the call.

“Such a deal would not block Iran’s path to the bomb. It would pave it. It would increase the risks of nuclear proliferation in the region and the risks of a horrific war. The alternative is standing firm and increasing the pressure on Iran until a better deal is achieved,” he added.

Obama, calling from aboard Air Force One, countered that the deal “represents significant progress towards a lasting, comprehensive solution that cuts off all of Iran’s pathways to a bomb and verifiably ensures the peaceful nature of Iran’s nuclear program going forward,” according to a read-out released by the White House.

Obama said the deal “in no way diminishes our concerns with respect to Iran’s sponsorship of terrorism and threats towards Israel and emphasized that the United States remains steadfast in our commitment to the security of Israel,” the White House said.

The US president told Netanyahu that he instructed his security team to “increase consultations with the new Israeli government about how we can further strengthen our long-term security cooperation with Israel and remain vigilant in countering Iran’s threats.”

Times of Israel staff contributed to this report.