Canada, which had 57 citizens on the flight, has said France would the best place to send the black boxes because it was one of the few nations with the ability to read them.
Iran's civil aviation agency has released its second preliminary investigative report on the accidental shooting down of a Ukrainian passenger plane near Tehran earlier this month.
"French and USA accident investigation agencies have refused to send necessary equipment to Iran for decoding the "black boxes", reads the report.
Iranian officials have offered contradictory remarks on whether they'll send the plane's flight data and cockpit voice recorders overseas to be analyzed.
Iran admitted Tuesday that the anti-aircraft missiles its armed forces fired at a Ukrainian passenger plane earlier this month were made by Russian Federation.
"So far, these countries have not responded positively to the shipment of the equipment to (Iran)", he said.
That was carried out in reprisal for a January 3 USA drone strike that killed Iran's most prominent military commander, Qasem Soleimani, near Baghdad airport.
US rejects extradition request from United Kingdom over fatal road crash
On Friday, Dominic Raab, Britain's worldwide secretary, mentioned he had spoken by phone with U.S. In a statement, the State Department said Sacoolas extradition would set a troubling precedent.
Ukraine insisted Monday that Iran hand over the black box flight recorders of a passenger plane mistakenly shot down by Iranian forces during a spike in tensions with Washington. Tehran has not yet decided whether the black box will be sent overseas or not.
However, the TSB said Thursday the black boxes are still in Iran and Iranian authorities are looking at trying to download the information there.
The first Canadian victim from a passenger plane downed by an Iranian missile strike has been brought home for burial.
The nine crew members killed were Ukrainian nationals, the remaining passengers included 146 Iranians, 10 Afghans, four Swedes and two Ukrainians, according to the report, although he acknowledged that some of the passengers could have dual nationality.
It has since slapped punishing sanctions on Iran, which denies it wants to acquire nuclear weapons and has hit back by progressively rolling back commitments to the unravelling nuclear deal signed in 2015 between Tehran and world powers. Iran's ISNA news agency reported Canadian transportation investigators visited the site after meeting with experts from Iran, Canada and Ukraine in Tehran.
Responding to US President Donald Trump's "maximum pressure" campaign created to shut off Iran's oil exports, Tehran has scaled back its commitments to the nuclear accord.
The Iranian military announced on the morning of January 11 that the plane had been mistaken for a cruise missile.
Most of those killed were Iranians.