The aircraft accident investigating board of Iranian and Ukrainian experts is investigating the black box according to standards of International Civil Aviation Organization (ICAO), Eslami was quoted as saying. He said if the examination team cannot decipher the data, another decision will be made.

Last month, the Ukrainian Boeing 737-800 aircraft flying from Tehran to Kiev crashed near Tehran's Imam Khomeini International Airport, killing all 176 passengers and crew members on board.

Later, Iran's armed forces confirmed that an "unintentional" launch of a military missile shot down the Ukrainian airliner.