Iran must give access to the black boxes from a Ukrainian airliner shot down by an Iranian missile in early January, Canada's foreign minister said on Wednesday.

"We do expect and we demand... from Iran to give access to the black boxes without any further delay," Francois-Philippe Champagne said during a press conference with his Ukrainian counterpart in Kiev.

Champagne stressed that it has been more than 30 days since the accident killing all 176 on board, and that Iran will "undermine the international law" if it chooses to keep the recorders.

"We have questions and we expect Iran to provide answers," the minister said.

The Kiev-bound Ukraine International Airlines Boeing 737 crashed shortly after taking off from Tehran on January 8
The Kiev-bound Ukraine International Airlines Boeing 737 crashed shortly after taking off from Tehran on January 8 AFP / -

"We hope that Iran will choose the way of transparency."

The Kiev-bound Ukraine International Airlines Boeing 737 crashed shortly after taking off from Tehran on January 8.

Tehran admitted several days later it had accidentally shot down the airliner during a confrontation with the United States -- Iran had launched missiles at US forces in Iraq in response to the killing of top general Qasem Soleimani on January 3.

The victims were mostly Iranian and Canadian citizens, as well as a Ukrainian crew.

Ukraine and Canada have repeatedly pressed Tehran to hand over the black box flight recorders to Kiev or Paris, but they remain in Iran.