TEL AVIV, Israel — Israeli leaders continued itsefforts to discredit the framework agreement between the P5+1 world powers and Iran, and insisted there are strong and viable alternatives to the deal.

Prime Minister Benjamin Netanyahu — perhaps the loudest vocal opponent to the deal — repeated his two formidable alternatives on Sunday.

He suggested that a better deal must "significantly roll back" Iran's nuclear capabilities. One way of doing so, he argued, would be to "shut down the illicit underground facilities that Iran concealed for years from the international community," he said in a statement.

Additionally, he also called for easing restrictions to Iran's nuclear program only if Iran puts an end to its "aggression" toward in the Middle East, "its worldwide terrorism and its threats to annihilate Israel."

Iran's insistence on immediate removal of sanctions, stalling the inspection process and increased presence in Yemen and elsewhere are the most pressing concerns for Netanyahu.

His Netanyahu's response comes a day after US President Barack Obama staunchly defended the deal and his hope for achieving a comprehensive agreement by the June 30 deadline.

Speaking at a press conference in Panama, Obama noted that the framework agreement is not set in stone and the final terms established at the end of June are likely to change.

"The details make a big difference, how they're structured. And, I guarantee you there will be some tough negotiations surrounding that," he Obama said.

US President Barack Obama speaks during a press conference at the Summit of the Americas at the ATLAPA Convention Center on April 11, 2015 in Panama City. AFP PHOTO/MANDEL NGAN
US President Barack Obama speaks during a press conference at the Summit of the Americas at the ATLAPA Convention Center on April 11, 2015 in Panama City. AFP PHOTO/MANDEL NGAN

US President Barack Obama speaks during an April 11 press conference at the Summit of the Americas in Panama City.

Photo Credit: Mandel Ngan/AFP

Obama specifically singled out Israel and its opposition to the deal, arguing that Israeli expectations are constantly shifting and are unable to be met.

"Once we actually got through negotiations, it actually turned out we had something that was substantial … that has proven to be highly effective, even by the assessments of critics of the policy like the Israelis … but, you know, consistency is the hobgoblin of narrow minds," he Obama said flippantly, in what was most likely a targeted rebuke at Netanyahu.

The dig is only the latest in the diplomatic ping-pong between the two leaders, where their disdain for each other grows more tangible by the day.

Meanwhile, Zionist Union leaders Isaac Herzog and Tzipi Livni attempted to offer alternatives of their own, with the criticism targeted more toward Netnayhu than Obama.

Israeli co-leader of the Zionist Union party and Labour Party's leader, Isaac Herzog speaks during a joint press conference at the party headquarters in the Israeli coastal city of Tel Aviv on March 18, 2015 a day after the country's general election. After a closely-fought campaign, Israeli Prime Minister Benjamin Netanyahu's rightwing Likud party confounded the polls to win 30 of the 120 seats in parliament against 24 for rivals the centre-left Zionist Union. AFP PHOTO / JACK GUEZ
Israeli co-leader of the Zionist Union party and Labour Party's leader, Isaac Herzog speaks during a joint press conference at the party headquarters in the Israeli coastal city of Tel Aviv on March 18, 2015 a day after the country's general election. After a closely-fought campaign, Israeli Prime Minister Benjamin Netanyahu's rightwing Likud party confounded the polls to win 30 of the 120 seats in parliament against 24 for rivals the centre-left Zionist Union. AFP PHOTO / JACK GUEZ

Israeli co-leader of the Zionist Union Party and Labor Party's leader Isaac Herzog speaks during a March 18 press Tel Aviv.

Photo Credit: Jack Guez/AFP

Herzog lost to Netanyahu in Israel's general election last month. Negations to form a coalition government are underway with a deadline set for April 22.

A document released on Sunday by Herzog's center-left party argued that there should be a tacit agreement with the US that if Iran were to infringe on the its agreement with the US, Washington would should publicly back Israel's right to use force while keeping its own military option "muscular and viable."

"If Iran will break out to the bomb, all actions, including new sanctions and the military option, will continue to be on the table at all times," the party wrote.

The argument urged for strong strategic cooperation with the US in order to ensure Israel's long-term security when faced with the threat of a nuclear Iran.

Advocating for an "American umbrella" of protection, the document called for "an empowering and expanding of the IDF's defensive and offensive capabilities, a strengthening of the existing alliance and strategic cooperation that will increase Israel's deterrence ability, in a way that will give Israel an American umbrella and the unrestricted ability to act against threats and violations both of the deal and against our regional enemies that are supported by Iran."

Even though there is a consensus among most Israeli security experts regarding the Iranian file, the party suggested that Netanyahu's current approach has further isolated Israel and placed it in a difficult position to influence world powers.

"Instead of a policy that leaves Israel without a meaningful influence on the world powers' decision-making process, Israel must immediately hold a comprehensive, intimate and deep strategic discussion with the US about all of the relevant issues and to complete the discussion before the completion of the final agreement," the document read.

It The Zionist Union report argued that sanctions must only be gradually lifted if the Iranians demonstrate that it has curbed its nuclear ambitions. Like Netanyahu, Herzog also called for frequent and intrusive inspections of Iranian nuclear facilities and eliminating its stockpile of enriched uranium.