Welcoming visitors through the door with a smile and wearing a crown of Ukrainian flags, Liana Khobot works two shifts a day -- one in her job and one at the volunteer centre.

She is one of the thousands of Ukrainians who have mobilised to volunteer to feed soldiers, distribute humanitarian supplies and make military paraphernalia since Russia invaded on February 24.

While millions of Ukrainians have fled into neighbouring European countries in the face of a brutal Russian offensive, Khobot wants to stay in the central Ukraine city of Dnipro to help.

"My friend is in Warsaw now. We've known each other for 40 years. I'll stay here. I will not leave. It's my country, my land, my city," she told AFP.

On Monday -- known as Volunteer Day in Ukraine -- President Volodymyr Zelensky thanked the nation for answering the "call to defend Ukraine," saying that all Ukrainians are volunteers now.

From the military to journalists, civilian reservists, food and humanitarian aid suppliers, doctors and firemen, "I sincerely congratulate you," he said in a video statement.

Dnipro, an industrial city of one million inhabitants, has been largely spared by the Russian advance
Dnipro, an industrial city of one million inhabitants, has been largely spared by the Russian advance AFP / Emre CAYLAK

Khobot, 58, gets up at 6:00 am every day to go to her job as a pharmaceuticals distributor before coming to the Volunteer Dnipra centre on the banks of the river Dnieper.

There, she receives donations and coordinates supplies for the Territorial Defence, a civilian militia, and the army.

She also helps to house displaced families who arrive shaken and scared from cities in the country's eastern Donbas region, which has experienced some of the fiercest fighting.

At the centre, even teenagers, usually known for their surliness, help by cutting fabric to make bullet proof vests and other military garb.

Thousands of Ukrainians have mobilised to volunteer to feed soldiers and distribute humanitarian supplies
Thousands of Ukrainians have mobilised to volunteer to feed soldiers and distribute humanitarian supplies AFP / Emre CAYLAK

Their work is getting harder by the day, however, due to the lack of available supplies.

Yulia Dmytrova, 35, the deputy director of social policy in Dnipro's city council, helped to set up and now coordinates the volunteer centre.

"Dnipro is the centre of everything right now because it's relatively safe. We have refugees and soldiers, and they need clothes, beds, mattresses and we collect it here for them," she said.

"We get help from western Ukraine, Poland and the West. We have plenty of people willing to help us here but what we really need -- and we demand -- is the guarantee of humanitarian corridors to deliver things safely."

Dmytrova says that they have tons of supplies ready for transportation to Donbas, but a lot of it is stuck in Poland.

The journey to the east is dangerous as fighting continues, with agreed humanitarian corridors often fired at, such as those to besieged Mariupol and Volnovakha.

The fight is edging closer to Dnipro though and on Tuesday, its airport was targeted by Russian strikes, sending plumes of dark smoke into the sky.

After earlier failed attempts, dozens of cars were able to leave the surrounded port city of Mariupol on Monday.

Officials say more than 2,000 residents have been killed there since the beginning of the invasion and Russian troops encircled the city.

Dmytrova said it was this, securing humanitarian routes, where the West could be of greatest help.

"If the international community can do one thing to help us, let it be this," said Dmytrova.