Iran live updates: Trump honors troops killed in Iran war during Memorial Day remarks

President Donald Trump on Monday again insisted that his proposed Iran deal is the "exact opposite" of former President Barack Obama's nuclear deal with Iran, attacking Democrats and his GOP adversaries in a new social media post.

"The deal with Iran will either be a great and meaningful one, or there will be no deal. It will be the exact opposite of the JCPOA disaster negotiated by the failed Obama Administration, which was a direct and open path to a Nuclear Weapon for Iran. No, I don't do deals like that!" Trump wrote.

The president said that his critics "know nothing" about the potential deal he is working on, adding that "things haven't even been negotiated yet." On Saturday, Trump claimed an "agreement had been largely negotiated."

Trump also criticized his Republican adversaries, including Sen. Bill Cassidy, Rep. Thomas Massie, and Sen. Thom Tillis. While pointing to Cassidy and Massie's recent primary losses, Trump added that Tillis is also "Soon out of office!"

In a subsequent post, the president wished Americans a happy Memorial Day, "including the Dumocrats, who disrespect our Military and all of the tremendous success that it has had over the last year."

-ABC News' Emily Chang

Iranian Foreign Ministry spokesperson Esmail Baghaei told a Monday press conference that the U.S. and Iran have "reached a conclusion on a large part of the issues under discussion," though stressed that "no one" can say that the finalization of a deal is "imminent."

Tehran is "witnessing frequent changes in positions" from the U.S. side, Baghaei said, as quoted by the state-run Islamic Republic News Agency.

"Within a few hours you will encounter different and in many cases contradictory views," Baghaei told reporters of the talks.

Baghaei also addressed different facets of a possible deal, saying a ceasefire of the war on all fronts -- including Lebanon -- was part of the draft agreement. He also said details about the management of the Strait of Hormuz are still undecided.

"We have not entered into the details of this agreement. How the Strait of Hormuz will be managed is a matter that concerns the coastal states of the strait," Baghaei said.

He added that no Iranian delegation visit to Pakistan, the mediating country, is planned at the moment.

"We are now focused on the negotiation process. How the understanding will be announced or signed later is an issue that there is time to decide on in the future," Baghaei said.

-ABC News' Victoria Beaule

Secretary of State Marco Rubio tempered expectations for a possible deal to end the U.S.-Israeli war with Iran while gaggling with the press before departing for Agra, India, overnight amid his ongoing visit to the country.

Rubio said an Iran deal is still a "work in progress" but signaled confidence that the disruption to shipping in the Strait of Hormuz can be addressed.

"We have what I think is a pretty solid thing on the table in terms of their ability to open up the straits, get the straits open, enter into a very real, significant, time-limited negotiation on the nuclear matters, and hopefully we can pull it off," Rubio said.

Rubio attributed the delay in negotiations to the "Iranian system."

Regarding Lebanon -- where Israeli strikes and Hezbollah attacks continue despite a ceasefire agreed by Israeli and Lebanese leaders -- Rubio said the U.S. delegation is working on that deal separately from any agreement that is made with Iran.

"Lebanon, we're working on separately. With Lebanon, we are engaged now. We have a 45-day ceasefire. We've had weekly meetings now, and ongoing daily engagements between the government of Lebanon and Israel," Rubio said. "The problem is not Lebanon and Israel; the problem is Hezbollah."

"As long as an armed Hezbollah exists, it's going to be hard to achieve peace in Lebanon," Rubio said.

Asked if a ceasefire would include Israel stopping strikes within Lebanon, Rubio said Israel has the right to defend itself and to prevent strikes against Israel from within Lebanon. The issue is "being understood during the ceasefire, and now in Lebanon, and it'll be understood beyond that," Rubio said.

-ABC News' Alex Ederson

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