"I am hoping that in the coming days we are not going to lose this momentum and we can close the deal," Josep Borrell said after an informal meeting of EU foreign ministers in Prague.

"It's clear that there is a common ground, that we have an agreement that takes into account, I think, everyone's concerns," he said.

The European Union put forward on August 8 what it called a final text to restore the landmark 2015 agreement that was trashed by former US president Donald Trump.

President Joe Biden took office with a goal of restoring the agreement, believing it was the best way to constrain Iran's nuclear programme and that Trump's withdrawal had done nothing but lead Tehran to accelerate its nuclear work.

The new proposal would see Iran get sanctions relief and be able to sell its oil again in return for severe limits on its nuclear programme.

Both Iran and the US have responded with a series of proposed changes.

But Iran's arch-rival Israel has stepped up pressure on Western nations to block the deal.