The Islamic republic has held talks since April in Vienna with major powers on reviving its troubled 2015 nuclear agreement.

The accord offered Tehran international sanctions relief in exchange for limiting its nuclear programme, but was torpedoed in 2018 when former US president Donald Trump withdrew from it and reimposed sanctions.

"The work was ready" to be done, the moderate Rouhani said of the talks, speaking in a televised cabinet meeting.

But "they took away the 12th administration's opportunity," he added about his government, without elaborating. "We hope the 13th administration can finish this work."

Rouhani is set to hand power in early August to the ultraconservative former judiciary chief Ebrahim Raisi, who last month won a presidential poll.

Trump's successor Joe Biden has signalled his readiness to return to the deal and has engaged in indirect negotiations with Iran as the accord's remaining other state parties -- Britain, China, France, Germany and Russia -- hold talks in Vienna.

They have held six rounds of talks, concluding the latest on June 20 without setting a date for a new one.

- Decision time -

The United States and France warned Iran in late June that time was running out to revive the deal, to which Tehran responded by saying that it expects others to "take the decisions".

Iran's ultraconservative camp, which deeply distrusts the United States, has repeatedly attacked Rouhani over the failing nuclear deal, which was reached six years ago on Wednesday.

Despite this, Iran's senior political figures, including Raisi, have voiced broad agreement that the country must seek an end to the punishing US sanctions.

"Any negotiations that guarantee national interests will certainly be supported, but... we will not allow negotiations to be for negotiations' sake," Raisi said on June 21.

He added that "any meeting must produce a result ... for the Iranian nation".

Rouhani's government has insisted that Iran's basic position on the nuclear talks will remain the same.

Ultimate political power in Iran rests with the supreme leader, Ayatollah Ali Khamenei, who gave the green light to both the original nuclear agreement and the efforts to revive it.

In his speech, Rouhani also insisted that his government has "done what was required" to lift US sanctions and that Iranians could "clearly see" their efforts in a foreign ministry report released Monday.

The report mentioned in broad terms what has been agreed to in Vienna and included a note from Foreign Minister Mohammad Javad Zarif, who called on all political forces to work together to succeed in the talks.