A possible meeting on resurrecting the Iran nuclear deal could be held "this week" after Tehran submitted its response to an EU proposal, the European Union's top diplomat has said.

"A meeting was scheduled to take place in Vienna at the end of last week, but it was not possible," EU foreign policy chief Josep Borrell told a news conference in Santander, Spain on Monday.

"It is possible that it could take place this week."

Borrell also said he hoped the United States would respond positively as early as this week to an EU proposal that aims to save the 2015 deal with Iran.

He said Iran had given a "reasonable" response to the proposal, which follows 16 months of irregular, indirect US-Iranian talks with the EU shuttling between the parties. The contents of the proposal have not been made public.

"There was a proposal from me as coordinator of the negotiations saying 'this is the equilibrium we reached, I don't think we can improve it on one side or the other'...and there was a response from Iran that I considered reasonable," Borrell said in Santander.

"It was transmitted to the US which has not yet responded formally...I hope the response will put an end to the negotiations," he added.

An EU official has previously said the proposal is the bloc's "final offer" to revive the pact suspended in 2018 by the administration of then-US president Donald Trump.

Analysts say the stakes are high, since failure in the nuclear talks could carry the risk of a fresh regional war, with Israel threatening military action against Iran if diplomacy fails to prevent Tehran from developing a nuclear weapons capability.

Iran has warned of a "crushing" response to any Israeli attack.

Earlier on Monday, Iran's Foreign Ministry spokesperson Nasser Kanaani accused the US of "procrastinating" in the negotiations.

"The US government is responsible for the current situation, and if it shows its political determination in action seriously and alongside promise and comment, acts responsibly, we can move toward the next stage," Kanaani said.

Talks on reviving the accord started in April 2021, and took a pause following the election of Ebrahim Raisi as Iran's president in June of that year, before resuming in November.

The deal formally known as the Joint Comprehensive Plan of Action, or JCPOA, was designed to prevent Iran from developing a nuclear weapon — something it has always denied wanting to do.