Iran’s diplomatic efforts had been damaged by the interventions of military men such as assassinated Revolutionary Guards commander Qassem Soleimani, the country’s foreign minister and nuclear negotiator Mohammad Javad Zarif said in a leaked recording.

“Many diplomatic prices that we paid were because the [military] field was a priority,” Zarif said in a secret interview recorded on February 24 as part of an “oral history” research scheme that was leaked on Sunday. “We paid for the [military] field but the [military] field did not pay for us.”

He said Soleimani — who ran Iran’s foreign military operations in the Middle East and was killed in a US drone strike in Iraq in January 2020 — used to tell him what to do in his negotiations with foreign dignitaries.

“Almost every time I went for talks, it was Martyr Soleimani who said: ‘I want you to get this advantage, this point’. He said: ‘When you go to talk to [Russian foreign minister] Lavrov, get 1, 2, 3, 4.’ . . . If I had said don’t use, for instance, Iran Air [civilian] planes on the Tehran-Syria route [for military purposes], he would not have accepted.”

For Iranian officials, speaking out against the Revolutionary Guards, the main ideological arm of the Islamic Republic, or their military operations in the region, which Iran’s top leaders consider vital for their survival, can come with a cost.

The comments come as Iranian diplomats have been negotiating in Vienna this month to help revive the nuclear deal that Zarif struck with world powers in 2015.

Donald Trump pulled the US out of the accord in 2018 and imposed tough sanctions that undermined pro-reform forces such as Zarif. New president Joe Biden has expressed willingness to return to the agreement and is in indirect negotiations with Iran in the Austrian capital.

The prospect of reaching a fresh agreement with the US has further complicated Iran’s domestic politics ahead of a presidential election on June 18 that will bring an end to the centrist government of Hassan Rouhani after two terms in office. Reformists consider Zarif their best choice to win the election and push for revival of the nuclear accord.

Should Zarif accept reformists’ call to run, he could be a game changer, analysts say. If he does not run, hardliners — mainly based in the Revolutionary Guards, the judiciary and parliament — believe they could have an easy ride in the polls.

Hardline forces are determined to discourage Zarif, reformists say, or else would try to disqualify him during the strict vetting procedures on candidates carried out by the Guardian Council, the hardline constitutional watchdog.

A regime insider close to hardliners said the leaked file would not be used to remove Zarif from office now. He did not comment further. But a reformist politician said the document could be used to disqualify the foreign minister.

In the interview, Zarif said he was not willing to run for president. “The world is moving forward . . . These months are vital. I want to focus on foreign relations, not domestic politics.”

The file was first disclosed by the London-based Persian-language television channel Iran International, which the republic considers a hostile body funded by Saudi Arabia. Iran International denies it is funded by or has any connection to Saudi Arabia. Some other Iranian media ran the three-hour interview, too, which was also listened to by the Financial Times.

Iran’s foreign ministry said the controversial parts had been taken “out of context” and were part of a seven-hour interview that could be published if “concerned” authorities allowed it, without giving further details.

Although the Islamic Republic considers Russia an ally, Zarif alleged on the tapes that Moscow had tried to sabotage the nuclear deal. He also said the Revolutionary Guards had hidden the fact that they had shot down an Ukrainian passenger jet last year. The tragedy, in which all 176 passengers and crew were killed, came hours after Iran responded to the killing of Soleimani by launching missiles at a US military base in Iraq. Zarif said he had no idea about the attack.

The worldview of the Islamic Republic’s leaders, he said, was “based on a polarised cold war” and that “a minority that are capable of creating huge waves” had their “interests in highlighting security so that their roles can be outstanding”.

“From the beginning, I told [Iranian diplomats that] we come to be sacrificed, not to be champions,” said Zarif.