The High Representative of the European Union for Foreign Affairs and Security Policy Josep Borrell at a Foreign Affairs Council meeting at the European Council headquarters. Photograph by Valeria Mongelli / Hans Lucas

The European Union’s foreign policy chief said on Monday he hoped the United States would respond positively as early as this week to an EU proposal that aims to save a 2015 nuclear deal with Iran.

Josep Borrell also said 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. 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 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,” he added.

An EU official has previously said the proposal is the bloc’s “final offer” to revive a pact suspended 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 fresh regional war, with Israel threatening military action against Iran if diplomacy fails to prevent Tehran from developing a nuclear weapons capability.

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

Earlier on Monday, Iran‘s Foreign Ministry spokesperson Nasser Kanaani accused the United States of “procrastinating” in the negotiations.

“The world would be a much safer place if we can make this agreement work,” Borrell said.