The United States is ready to "quickly conclude a deal" to revive the 2015 Iran nuclear agreement on the basis of proposals put forward on August 8 by the European Union, a State Department spokesperson said.
The spokesperson said Tehran had repeatedly said it was prepared for a return to mutual implementation of the agreement, and now Washington will wait to see if "their actions match their words."
The European Union earlier submitted a "final text" at talks in Vienna to revive the agreement.
"We worked for four days and today the text is on the table," the official told reporters. "The negotiation is finished, it's the final text...and it will not be renegotiated."
EU foreign policy chief Josep Borrell said on Twitter that everything that could be negotiated had been negotiated, adding that behind every part of the proposal "lies a political decision that needs to be taken" in the capitals of the countries involved.
He said the most recent talks were used to "fine tune and address" a handful of issues remaining in the text that he put on the table on July 21.
An Iranian Foreign Ministry official told state news agency IRNA that Iran had given its preliminary response to the EU's text but was "not at a stage to talk about finalizing the deal."
Tehran will "convey its additional views and considerations after more comprehensive discussions in Tehran," the official said, according to IRNA.
Top negotiators involved in the talks have said they are optimistic about the possibility of reaching an agreement.
Enrique Mora, the European Union's top negotiator, said over the weekend he was "absolutely" optimistic about the talks' progress so far.
"We are advancing, and I expect we will close the negotiations soon," Mora told Iranian media told Iranian media on August 7.
Russian Ambassador Mikhail Ulyanov said on August 7 there were "three or four issues" left to be resolved.
"We stand five minutes or five seconds from the finish line," Ulyanov told reporters outside the Palais Coburg hotel where the talks are being held.
SEE ALSO: The Farda Briefing: For The First Time, Iran Raises The Possibility Of Building A Nuclear BombA successful conclusion can be reached "very soon, but no guarantees -- as always, nothing is agreed until everything is agreed," he said.
"They are sensitive, especially for Iranians and Americans," Ulyanov said. "I cannot guarantee, but the impression is that we are moving in the right direction."
Negotiators from Iran, Russia, and the EU -- as well as the United States, indirectly -- resumed talks over Tehran's nuclear deal on August 4 after a months-long standstill in negotiations.
Washington unilaterally withdrew from the nuclear pact under then-President Donald Trump in 2018. Iran reacted by gradually backtracking on its obligations under the deal, such as uranium enrichment.
Iran struck the nuclear deal in 2015 with the U.S., France, Germany, Britain, Russia and China. The deal saw Iran agree to limit its enrichment of uranium under the watch of U.N. inspectors in exchange for the lifting of economic sanctions.
Iranian Foreign Minister Hossein Amir-Abdollahian said on August 7 in a phone call with UN Secretary-General Antonio Guterres that his country is "serious about reaching a strong and lasting agreement." But he added that the outcome will depend on whether the United States wants to make an agreement.
U.S. Special Envoy for Iran Rob Malley said last week that U.S. expectations for the Vienna talks are "in check" but the United States is prepared for a good faith effort to reach an agreement.
For their part, Britain, France, and Germany have called on Iran "not to make unrealistic demands" in the talks aimed at reviving the nuclear deal.