Josep Borrell, the EU's top diplomat, said that he hoped EU and Iranian diplomats would meet soon to try and restart nuclear talks, but he declined to confirm reports of a meeting in Brussels on Thursday.

A report mentioned that Iran's foreign minister provided the date on Sunday, citing an Iranian lawmaker. A senior EU official confirmed that meetings were planned in Brussels rather than Vienna, but provided no date.

"You never know, I'm more optimistic today than I was yesterday. No confirmation yet, but things are improving, and I hope to have preliminary meetings in Brussels in the upcoming days," said Borrell.

The chief coordinator for the discussions, EU political director Enrique Mora, was in Tehran last Thursday to meet with members of Iran's nuclear negotiating team, 4 months after talks between Iran and world powers fell down.

So far, Iranian President Ebrahim Raisi has declined to resume indirect discussions with the US in Vienna on both sides returning to compliance with the deal, under which Iran curtailed its nuclear programme in exchange for relief from economic sanctions.

However, following Mora's visit, Iran's foreign ministry announced that it would hold discussions with the EU in Brussels in the coming days.

Western diplomats have expressed concern that Tehran's new negotiating team - under a president recognised as an anti-Western hardliner, contrary to his pragmatic predecessor - could make new demands beyond the scope of what has already been negotiated.

Iran has long denied any desire to obtain nuclear weapons.