The European Union's top diplomat Josep Borrell said on Monday he hoped EU and Iranian diplomats would meet soon to try and revive nuclear talks but declined to confirm reports of a meeting in Brussels on Thursday.

Bloomberg News reported that Iran's foreign minister gave the date on Sunday, citing an Iranian lawmaker. A senior EU official last week confirmed that meetings were planned in Brussels, rather than Vienna, but gave no date.

"You never know, I am more optimistic today than yesterday," Borrell said. "No confirmation yet, but things are getting better and I am hope we will have preparatory meetings in Brussels in the days to come," Borrell said in Luxembourg as he arrived for an EU foreign ministers meeting.

EU political director Enrique Mora, the chief coordinator for the talks, was in Tehran last Thursday to meet members of Iran's nuclear negotiating team, four months after discussions broke off between Iran and world powers.

Iranian President Ebrahim Raisi has so far refused to resume indirect talks with the United States in Vienna on both sides returning to compliance with the deal, under which Iran curbed its nuclear program in return for economic sanctions relief.

But after Mora's visit, Iran's foreign ministry said it would hold talks in the coming days with the EU in Brussels.

Western diplomats have said they are concerned Tehran's new negotiating team - under a president known as an anti-Western hardliner, unlike his pragmatist predecessor - may make new demands beyond the scope of what had already been agreed.

Iran has long denied any ambition to acquire nuclear weapons.