Speaking at a news conference in the Qatari capital Doha, Borrell was referring to the talks between Tehran and other remaining parties to the nuclear deal – Russia, China, Britain, France and Germany – in Vienna that began in April and were adjourned in June when Iran’s presidential election was held and Seyyed Ebrahim Raeisi won it.
Borrell said he believed the negotiations aimed at bringing back the United States into compliance with the agreement, known as the JCPOA, will resume "within an acceptable period of time", Reuters reported.
Former US president Donald Trump ditched the deal three years ago and reimposed sanctions lifted under the JCPOA. President Joe Biden aims to rejoin the deal, but the sides disagree on which steps need to be taken and when.
Iran says the nuclear steps it took is response to the US withdrawal are reversible if Washington lifts all sanctions. Iranian and Western officials have said many issues remain to be resolved before the accord can be revived.
'Certainly will return'
Echoing Iran's official stance, Iran's Foreign Ministry spokesman told Le Monde newspaper that "Iran has reached conclusion that we certainly will return to the nuclear talks" in Vienna.
Saeed Khatibzadeh added that Iran would not "waste an hour before returning to Vienna talks once a re-evaluation of the sixth round of the nuclear talks" is completed by Raeisi's government.
"The Biden administration should finally make a decision: Either it wants to preserve Trump's legacy or it wants to build Biden's. This is a purely political decision," said Khatibzadeh, adding that "we don't have a lot of time ahead of us".
US and European officials told Reuters on Tuesday that Washington has reached out to China diplomatically about reducing its purchases of Iranian crude oil.
When asked about this, Chinese Foreign Ministry spokeswoman Hua Chunying said on Wednesday: "We firmly oppose any unilateral sanction, and urge the US to remove the so-called 'long-arm jurisdiction' over third-party entities and individuals as soon as possible."