Russia has demanded Ukrainian forces lay down their weapons in the besieged city of Mariupol, offering to facilitate a safe passage for civilians to escape in exchange for the surrender.
The Russian government gave Ukraine a deadline of the early hours of Monday morning to respond — but Ukraine rejected the offer, saying it would not surrender the port city.
Here's what we know about the ultimatum.
What did Russia demand?
Russia demanded that Ukrainians in the besieged city of Mariupol lay down their arms in exchange for safe passage out of town.
Russian news agency TASS reported that forces were going to allow two corridors out of the coastal city, heading either east toward Russia or west to other parts of Ukraine.
Russia's National Defence Management Centre chief Colonel General Mikhail Mizintsev told TASS that temporary humanitarian corridors out of Mariupol would be opened from 10am on Monday Moscow time (6pm AEDT) "upon the agreement with the Ukrainian side".
"Each Mariupol resident and foreign nationals will be guaranteed voluntary choice of any of the humanitarian corridors or the right to stay in the unblocked city," Colonel General Mizintsev told TASS.
Ukraine was given until 5am on Monday (1pm AEDT) to respond.
What has Ukraine said?
Basically, it said no.
Ukraine's Deputy Prime Minister, Iryna Vereshchuk, told the Ukrainska Pravda news portal there was "no question of any surrender" in Mariupol.
"We have already informed the Russian side about this," she said.
Ms Vereshchuk later said an agreement had been reached on creating eight humanitarian corridors to evacuate civilians from besieged towns and cities on Monday but the city of Mariupol was not among them.
She said efforts to reach Mariupol with humanitarian supplies continued to fail.
So are civilians able to escape?
Ukrainian authorities say some people have been able to leave in the past day or so, but it's unclear at this stage what Ukraine's rejection of Russia's offer will mean for those still in Mariupol.
The Berdyansk City Council said on Sunday that a convoy of buses travelling to Mariupol to assist with the evacuation was stopped by Russian forces a few kilometres away from the city, putting a question mark over the evacuation plans. However, it shared an update a few hours later saying the drivers "reached their destination safely".
"Today, 780 people left in 11 buses, and, as always, the priority is children, women and the elderly," Mayor Oleksandr Svidlo said.
"Also, thanks to the fuel reserves brought to the city for the residents of Mariupol. More than 200 cars managed to leave the city today.
"Tomorrow we are waiting for another (convoy) of buses to continue the evacuation."
Ms Vereshchuk said the Ukrainian government had plans to send dozens of buses to Mariupol on Monday to assist.
Who is still in Mariupol?
Mikhail Mizintsev told TASS that there were "up to 130,000 civilians" being held hostage in the city, including almost 200 foreigners.
He said Russia had helped evacuate 59,304 people out of the city. However, Mariupol's city council said on its Telegram channel late on Saturday that several thousand residents had been "deported" to Russia over the past week.
Prior to Russia's invasion of Ukraine, Mariupol had a population of close to 450,000.
There are reports that between 40,000 and 100,000 people have fled the city since, but there isn't an exact figure at this stage.
Ukrainian President Volodymyr Zelenskyy said nearly 4,000 people were evacuated from Mariupol on Sunday alone — but it was not clear where they went to.
What's the situation like on the ground?
There's still no electricity and very little access to food and drinking water for those still in Mariupol.
President Zelenskyy accused Russia of bombing an art school that was being used as a shelter for about 400 people on Sunday.
"They are under the rubble and we don’t know how many of them have survived," he said.
"But we know that we will certainly shoot down the pilot who dropped that bomb, like about 100 other such mass murderers whom we already have downed."
Multiple previous attempts to allow residents to evacuate Mariupol and other Ukrainian cities have failed or have been only partially successful, with bombardments continuing as civilians have tried to flee.
ABC/wires
