Iran has agreed in principle to a proposal that would include disposing of highly enriched uranium, a senior administration official told US reporters in a briefing on Sunday.
The official noted that efforts to close a deal were still underway.
The final agreement could see Iran reopening the Strait of Hormuz in exchange for the US lifting the blockade on Iranian ports.
CBS reported that the agreement would also see the US make accommodation for sanctions relief in exchange for Iranian accommodation on nuclear enrichment.
The administration official told reporters that there was a "broad commitment" on the principles of the documents, and that the Trump team feels positive about where negotiations stand.
Iran accuses US of blocking release of assets, says deal can still be canceled
The semi-official IRGC-affiliated Tasnim News Agency reported on the ongoing negotiations, claiming they were still at risk of collapsing.
According to Tasnim, the US was still blocking some clauses of the agreement, including the release of Iran's frozen assets.
"Iran has emphasized that it will not fall short of its red lines for the realization of people's rights," Tasnim declared.
White House says deal with Iran would take days to finalize
In the briefing to reporters, White House officials told reporters that they did not expect a deal to be reached on Sunday and believed that Iranian Supreme Leader Mojtaba Khamenei would take several days to approve any deal.
This comes after Iran denied agreeing to give up any enriched uranium in a US ceasefire deal, stating it had not yet accepted any action on the nuclear issue, Reuters reported Sunday morning.
The Memorandum of Understanding (MOU) - labeled the 'Islamabad Declaration' by Al Arabiya - reportedly states that both parties would sign a 60-day ceasefire extension and include the possibility of further talks and an extension during the two-month period.
If the MOU is approved by Iran's Supreme National Council, it will be sent to Mojtaba Khamenei for final approval.
On Sunday, Trump said on Truth Social that he told US representatives not to "rush in" to a deal with Iran.
"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," he wrote.
"Both sides must take their time and get it right. There can be no mistakes!"