It is hoped the United States will respond positively this week to a proposal that aims to save a landmark 2015 nuclear deal with Iran, the European Union (EU) has said.

Josep Borrell, the European Union foreign policy chief, also said on Monday that Iran had given a “reasonable” response to the proposal, which follows 16 months of fitful, indirect US-Iranian talks with the EU shuttling between the parties.

“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 told a university event in the Spanish city of Santander.

“It was transmitted to the United States, which has not yet responded formally … I hope the response will put an end to the negotiations. The world would be a much safer place if we can make this agreement work.”

Iran last week responded to the EU’s text with “additional views and considerations”, while calling on Washington to show flexibility to resolve three remaining issues.

Earlier on Monday, Iran’s foreign ministry spokesman Nasser Kanaani accused the US of “procrastinating” in the negotiations.

“America and Europe need an agreement more than Iran,” Kanaani told a news conference.

US State Department spokesman Ned Price denied Kanaani’s assertion, telling reporters in Washington, DC: “The notion that we have delayed this negotiation in any way is just not true.”

He said Washington was encouraged that Tehran seemed to have dropped demands such as the removal of its Islamic Revolutionary Guard Corps from the US Foreign Terrorist Organization list.

“That’s part of the reason why a deal is closer now than it was two weeks ago. But the outcome of these ongoing discussions still remains uncertain as gaps do remain,” Price said, adding the US was working as quickly as possible to provide its response.

‘Final offer’

The contents of the EU proposal have not been made public.

However, Al Jazeera Arabic has reported it includes the release of billions of dollars of frozen Iranian funds and the unblocking of Tehran’s oil exports – in return for the scaling back of its nuclear programme.

An EU official has previously said the proposal is the bloc’s “final offer” to revive the pact broken in 2018 by the administration of then-US President Donald Trump.

The stakes are high since failure in the nuclear talks would carry the risk of a regional war, with Israel threatening military action against Iran if diplomacy fails to prevent it from developing nuclear weapons.

Iran, which has long denied having such ambitions, has warned of a “crushing” response to any Israeli attack.