KYIV, March 11 - President Volodymyr Zelensky has hailed Ukraine's first-ever Oscar won by 20 Days In Mariupol - a documentary about Russia's brutal siege of the port city.

The film "shows the truth about Russian terrorism" Zelensky said.

The film provides rare testimony of the suffering of Mariupol's residents while their city is being destroyed.

Accepting the award for best documentary feature, director Mstyslav Chernov said he was "honored" to be Ukraine's first Oscar winner, BBC reported.

"Probably I would be the first director on this stage who will say I wish I would never have made this film," he said in his acceptance speech at the ceremony in Los Angeles.

"I wish to be able to exchange this [for] Russia never attacking Ukraine, never occupying our cities," he said, adding that Russia has killed "tens of thousands of my fellow Ukrainians".

Chernov urged everyone to make sure that "the history record is set straight, and that truth will prevail, and that the people of Mariupol and those who have given their lives will never be forgotten.

"Because cinema forms memories, and memories form history."

The director finished his speech by saying "Slava Ukraini!" (Glory to Ukraine!) - a historic rallying cry that is now being used by millions of Ukrainians in the country and across the world.

The film's recognition is being celebrated across Ukrainian social media, with one news channel calling it a "historic victory", says the BBC's James Waterhouse in Kyiv.

Chernov's team of three journalists documented the gradual encirclement of Mariupol by Russian forces in the first months of Russia's full-scale invasion in February 2022, and their film is a searing snapshot of what was inflicted on the people who lived there, our correspondent adds.

The team risked their lives filming there, and later somehow managed to leave the city by going through numerous Russian checkpoints with the filmed material hidden under a car seat.

Mariupol - the southern Ukrainian port on the Sea of Azov - was almost completely destroyed by Russian troops after months of fierce fighting. (bbc/ez)