The Ukrainian leader claimed he was counting on result in this case, and it's "not just about the black boxes".

"They promised other things, too. They have to apologize officially. They've got to pay adequate compensations... They have to do what they promised. Otherwise, we will have no other option - and they now our stance - but to turn to international courts", the President said.

Related: Iran ignores Ukraine's note on downing PS752 airplane, - MFA

He added that Iran explained the delay with passage of black boxes, referring to the Covid-19 pandemic, but "this problem cannot wait forever". 

Boeing 737, flight PS752 of Ukraine's International Airlines crashed near Tehran on the night from January 7 to 8. It belonged to UIA air company. 176 people were aboard, nine of them were crew members. Most of the deceased were citizens of Iran and Canada. 11 Ukrainians, two of them passengers, were among the dead as well.

On January 11, General Staff of Iran's Armed Forces claimed that the Ukrainian aircraft was downed by an anti-air missile, launched by the Islamic Revolutionary Guard Corps.

Related: Iran asks France to decrypt PS752's black boxes