France is planning a humanitarian operation with Turkey and Greece that will defy Russia’s siege of the devastated southeastern Ukrainian port city of Mariupol.

French President Emmanuel Macron announced the plan on Friday evening after an EU summit in Brussels.

There were already concrete talks with the mayor of Mariupol and co-ordination with Ukrainian President Volodymyr Zelenskiy, Macron said.

The key question will be Russia’s response to the evacuation initiave as its troops continue to mount a campaign of attrition to gain control of the historic and strategically vital Black Sea port.

According to the Elysee Palace, France is in contact with the Ukrainian authorities, the Greeks, the Turks and the relevant international organisations in order to specify the needs to be met.

The action should start in the next few days, according to Paris.

On Friday, local officials, citing witness accounts, said as many as 300 people may have been killed in the bombing of a theatre in Mariupol on March 16.

The city council made clear it was still not possible to determine the exact death toll after the incident, in which it said a powerful Russian air strike hit the Drama Theatre where hundreds of people had been sheltering in the encircled city.

Russia has denied bombing the theatre. The Kremlin says Russian forces have not targeted civilians during their invasion of Ukraine, which began on February 24.

-with AAP