The U.S. and Iran are making progress ironing out a two-step interim agreement in which the U.S. would get a broad "commitment" from Iran to negotiate a removal of their stockpile of enriched uranium, a senior administration official said on a call with reporters on Sunday morning.

This limited agreement includes an immediate opening of the Strait of Hormuz and end to the U.S. naval blockade there, the official said, as questions of how to dispose of the stockpiled radioactive material remain.

“We're going to do a deal where ... they will open up the Strait in exchange for us lifting the blockade, and they will agree in principle to dispose of the highly enriched uranium,” the official said. “That is currently where the substantive conversation’s focused.”

“Even if we get this language in a good place, it is going to take days for it to filter through their system and get an approval,” the official added.

The official offered no specific details on timing, both regarding how long this peace negotiation process could last and how long the nuclear material removal process could take.

Trump posted on his social media platform Saturday that “an Agreement has been largely negotiated” between the U.S. and Iran, “subject to finalization” between the parties involved. Secretary of State Marco Rubio said Sunday that the deal’s "ultimate goal is that Iran can never have a nuclear weapon."

Iran has not yet signed on to or publicly commented on the proposal.

-ABC News' Isabella Murray

As some Republican senators and former GOP officials warn that President Donald Trump's proposed deal with Iran would just be a repeat of the nuclear deal put in place during former President Barack Obama's administration, Trump is pushing back on that notion, saying his deal is the "exact opposite" of Obama's.

Obama's deal "was a direct path to Iran developing a Nuclear Weapon," Trump posted on his social media platform on Sunday. "Not so with the transaction currently being negotiated with Iran by the Trump Administration -- THE EXACT OPPOSITE, in fact!"

Trump went on to say that relationship between U.S. and Iran is becoming a "much more professional and productive one" and that there is 'no rush' to make a peace deal with the regime.

"The negotiations are proceeding in an orderly and constructive manner, and I have informed my representatives not to rush into a deal in that time is on our side. The Blockade will remain in full force and effect until an agreement is reached, certified, and signed. Both sides must take their time and get it right. There can be no mistakes!" Trump wrote.

Trump posted on his social media platform Saturday that "an Agreement has been largely negotiated" between the U.S. and Iran, "subject to finalization" between the parties involved. Secretary of State Marco Rubio said Sunday that the deal's "ultimate goal is that Iran can never have a nuclear weapon."

Iran has not yet signed on to or publicly commented on the proposal.

The Joint Comprehensive Plan of Action (JCPOA), which imposed restrictions on Iran's civilian nuclear enrichment program in exchange for sanctions relief, was signed on July 14, 2015, during the Obama administration. It was agreed to by Iran and the five permanent members of the United Nations Security Council -- China, France, Russia, the United Kingdom and the United States -- as well as Germany and the European Union.

The JCPOA was designed to ensure that Iran's nuclear program would be exclusively peaceful and provided for the lifting of nuclear-related sanctions in order to prevent Iran from developing nuclear weapons.

Two years after the deal went into effect, President Donald Trump withdrew the U.S. from the nuclear accord during his first term in office, saying at the time "it is clear to me that we cannot prevent an Iranian nuclear bomb under the decaying and rotten structure of the current agreement."

-ABC News' Isabella Murray

After announcing Saturday on his social media platform that "An Agreement has been largely negotiated" between the U.S. and Iran, President Donald Trump Sunday morning posted an AI-generated image of a drone aircraft with a U.S. flag on it launching an attack on two Iranian-flagged ships, with the image caption "Adios."

The image features smoke and flames billowing out of the Iranian ships, with bodies ejected from the vessels and falling into the ocean.

Trump said in his online post Saturday that the framework of the proposed deal is "subject to finalization" between the parties involved.

Iran has not yet signed on or publicly commented on the proposal.

Overnight, Secretary of State Marco Rubio said "significant progress" had been made in discussions with Iran. He added that that the administration has worked with Gulf regional partners over the last 48 hours on a possible framework aimed at keeping international waterways open and addressing concerns surrounding Iran's nuclear ambitions.

-ABC News' Emily Chang

Israeli Prime Minister Benjamin Netanyahu has not officially responded to President Donald Trump's remarks that a U.S. deal with Iran has been "largely negotiated."

But a statement attributed to an Israeli political source was distributed to the local press with details of the Israeli leader's call with Trump on Saturday that focused on the emerging deal.

"The U.S. is updating Israel on the negotiations for a memorandum of understanding to open the Strait of Hormuz and entering into negotiations for a final agreement on the points that are in dispute," the source said.

"In a conversation last night with President Trump, the prime minister emphasized that Israel will maintain freedom of action against threats in all arenas, including Lebanon, and President Trump reiterated this principle," the source added.

"President Trump made it clear that he will stand firm in the negotiations on his consistent demand for dismantling the Iranian nuclear program and removing all enriched uranium from its territory, and that he will not sign a final agreement without accepting these conditions," the source said.

Netanyahu "reiterated his appreciation to President Trump for his long-standing and extraordinary commitment to Israel's security," the source said.

-ABC News' Jordana Miller and Rashid Haddou-Riff

President Donald Trump said Saturday that a framework for a peace deal with Iran will be announced shortly and it will include opening the Strait of Hormuz.

In a lengthy social media post, the president said he spoke with several Middle Eastern leaders and "an Agreement has been largely negotiated, subject to finalization between the United States of America, the Islamic Republic of Iran, and the various other Countries."

"Final aspects and details of the Deal are currently being discussed, and will be announced shortly," he said.

The post added: "In addition to many other elements of the Agreement, the Strait of Hormuz will be opened."

-ABC News' Selina Wang