Ukrainian officials in charge of investigating the January 2020 downing of a Ukrainian passenger plane in Tehran say they have not yet received the documents promised by Iran.

On January 8, the Ukraine International Airline Boeing 737-800 took off from Tehran's Imam Khomeini international airport, heading to Kyiv. Minutes later, the Islamic Revolution Guards Corps fired two missiles at the plane. The three-year-old passenger plane crashed near the Iranian capital city of Tehran, killing all 176 people aboard.

The crash victims included 82 Iranians, 63 Canadians, 11 Ukrainians, ten Sweden, four Afghans, three Germans, and three Britons.

It took Iranian authorities three days to admit that the IRGC had fired the missiles at the passenger plane.

Since January 11, the IRGC and other Iran authorities have insisted that the missiles were "accidentally" and "mistakenly" fired at the UIA's plane.

The Ukrainian investigation team has not yet received the materials and evidence promised by Iran regarding the crash of the flight, the Russian Interfax news agency cited the press service of the Ukrainian Prosecutor General's Office of Ukraine as saying on Monday.

Ukrainian officials say the results of the investigation into the incident and how Iranian officials should pay compensation should be clarified as soon as possible.

"There is no point in negotiating for the sake of negotiation. Effective cooperation and results are important. And we must provide the answers as soon as possible because next January will be the anniversary of the plane crash," Deputy Prosecutor General of Ukraine, Gunduz Mamedov, said at a meeting with Tehran's Ambassador to Kyiv, Manouchehr Moradi.

Iran and Ukraine held two rounds of talks, in July in Kyiv and in October in Tehran.

The next round of talks, with other countries involved in the tragedy, was scheduled to occur within a month after the October gathering in Iran.