Iran's foreign minister on Sunday asked the family of Qasem Soleimani for "forgiveness" following his leaked comments that the revered late commander had played too big a role in diplomacy.

Soleimani, the commander of the Revolutionary Guards' foreign operations arm, was killed in a US airstrike in neighbouring Iraq last year.

Media outside Iran published the three-hour recording of Foreign Minister Mohammad Javad Zarif last Sunday, triggering a heated debate ahead of presidential elections and amid talks with world powers in Vienna to revive a nuclear deal.

"My remarks... do not diminish the status and irreplaceable role of martyr Soleimani," Zarif wrote on Instagram.

"The pure feelings of those who love the great martyr Major General Qasem Soleimani and his family, especially his brave daughter Zeinab -- who is as dear to me as my own children -- have been hurt," Zarif added.

Zeinab Soleimani posted a photo Tuesday on Twitter showing her father's hand shortly after being assassinated, calling it "the cost" paid by those in "the field for the sake of diplomacy".

In the audiotape, Zarif talked about the military having too much influence on diplomacy, and mentioned the significant role played by Soleimani.

"In the Islamic republic the military field rules," Zarif said in the recording, quoted by the New York Times. "I have sacrificed diplomacy for the military field rather than the field servicing diplomacy."

Zarif has been under fire from conservative politicians and media for the leaked recording, with remarks on Soleimani hitting a nerve.

"If I knew a word of them would be published publicly I would not have said them," Zarif said.

"I have forgiven all those I believe accused me ... I hope the great people of Iran, all those who love (Soleimani), and especially the gracious Soleimani family, forgive me as well," he added.