Iran's President Hassan Rouhani has said the country's military should elaborate more on how it shot down a passenger plane by mistake last week.
Separately, Foreign Minister Mohammad Javad Zarif acknowledged that Iranians "were lied to" for days afterwards.
He insisted that he and the president were also kept in the dark.
Iran's Revolutionary Guards killed 176 people when they "unintentionally" shot down the Ukrainian aircraft amid escalating tensions with the US.
Hours before, Iranian missiles had targeted two airbases in Iraq housing US forces.
"I and the president did not know [what brought the plane down] and, as soon as we did, we communicated it," said Mr Zarif, during a televised interview while on a trip to India.
He also praised the military for being "brave enough to claim responsibility early on" – however critics have decried the three-day delay and said they only owned up after Western authorities claimed to have contrary evidence.
New footage – verified by the New York Times – shows two missiles, fired 30 seconds apart, striking the plane. It was initially though to have been hit once.
Flight PS752 was brought down after it took off from Tehran on Wednesday last week, when the Revolutionary Guards – a force set up to defend the country's Islamic system – mistakenly perceived it as a threat amid escalating conflict with the US. Everyone on board died.
The deaths and the apparent initial cover-up – when the act was denied and the crash site was bulldozed – have sparked protests in various Iranian cities.
Police in the capital, Tehran, have been accused of using live ammunition against demonstrators.
Iran's Supreme Leader Ayatollah Ali Khamenei is expected to deliver Friday prayer sermons in the city this week for the first time since 2013, in an apparent bid to ease domestic tension.
How has Iran's crisis unfolded?
Last Wednesday, Iran launched a series of strikes on two military bases in neighbouring Iraq, which were housing US troops. It was a retaliatory move after US President Donald Trump ordered a strike in Iraq that killed top Iranian General Qasam Soleimani.
A few hours after the Iranian strikes, Flight PS752 crashed near Tehran in initially unclear circumstances, although Iran's authorities immediately blamed technical difficulties.
On Thursday, various Western powers – including Canada, which had 57 citizens onboard the plane – said they had evidence that Iran's military had downed the plane.
Iran reiterated its denials until Friday, when it conceded that the passenger jet was hit by its air defence systems.
Mr Zarif has now personally insisted that he and President Rouhani only found out about what had really happened on that day.
Brig-Gen Amir Ali Hajizadeh, the Revolutionary Guards' aerospace commander, has said a missile operator acted independently and alone, mistaking the plane for a "cruise missile" as there had been reports that such missiles Read More – Source