By Nick Beake

BBC News Europe correspondent

Media caption,

One of Ukraine’s biggest rock stars has held an impromptu solidarity concert on Kyiv’s glass bridge

Svyatoslav Vakarchuk is one of Ukraine’s biggest rock stars.

With more than a million followers on Twitter, he’s used to packing out venues across the country with his band Okean Elzy (Elza’s Ocean).

But now we’re all looking on nervously as he climbs gingerly onto the railings of a towering bridge in central Kyiv and slowly lifts his arms aloft.

It’s an apt image as the future of his homeland hangs in the balance.

“Everything will be fine,” he sings. The lyrics of one of his greatest hits embodies the calm fortitude the country is trying to project in the face of the latest Russian aggression.

Hundreds have gathered round and are now joining in the chorus. Hundreds of thousands will be watching this streamed online.

Russian President Vladimir Putin may have done a lot of talking recently, but this is the voice of Ukraine.

As the impromptu concert ends and Vakarchuk tries to weave his way through his legion of fans, I ask what message he wants to send.

“The destiny and the future of Ukraine is not only the destiny and the future of Ukrainians, but also for millions and billions of people who want to live in freedom, dignity and democracy,” he replies.

He says his country needs the world to step up and stand by Ukraine more than ever.

“The most important message is that Ukraine is united, we are strong. We are optimistic. We are looking into the future with wide open eyes, and we shall overcome.”

This sense of defiance is pulsing through the crowd that has gathered here in the heart of the capital.

We find a group of history students quietly reciting the national anthem with their palms resting on their hearts.

The opening words proclaim: “Ukraine’s glory hasn’t perished, nor freedom, nor will.”

Freedom is a word so many people we talk to reach for.

Tamila Kalytenko explains: “We will fight for our nation, our city, our country, our home. Everyone in Ukraine today is together.”

Image caption,

A group of students recited the national hymn

Maryna – only 15 years old – introduces herself.

She says her parents are proud that she’s trying to protect her own future and that of Ukraine.

“I’m not afraid,” he says, “I praise my armed forces. I think they will save us from this.”

But what if the situation got very bad, could you see yourself leaving, I ask.

“I will stay because it’s my country, my city and I will fight for my national identity.”

This outpouring of patriotic pride is manifesting itself in another, more material way.

In the small office of the military charity “Come Back Alive”, they can’t believe what they’re seeing on their laptop screens.

Taras Chmut, a former drone pilot in military intelligence, tells me they’ve received more online donations in the past 24 hours than in the whole of the last year.

It’s the equivalent of £500,000 ($677,000).

This means more of the thermal cameras, drones and landmine disarming kits stacked up on the tables will soon be making their way to the frontline to boost supplies for those who’ve been fighting Russian-backed rebels for the past eight years.

Image source, AFP

Image caption,

Taras Chmut says donations to military charity Come Back Alive have dramatically increased

A man who once staked out the enemy’s lines, Chmut fears that Russia will soon try to seize more land in the Donbas region and look to create a land corridor to the Crimean peninsula Moscow annexed in 2014.

But he vows Ukrainians would “fight to the last soldier and to the last civilian.”

His final analysis is stark: “It will not end well for Russia.”

It could be that many of those we talk to are more concerned privately than they would like to let on.

But although a 30-day state of emergency has now come into force, you do not detect a state of panic in Kyiv.

Image caption,

Reservist Viktoria Dvoretska says she will do whatever the army needs her to do

Sorting out parcels in the next door room at the charity is Viktoria Dvoretska.

She has the honour of being the first woman to have served as a frontline commander in the Ukrainian armed forces.

Three years ago she left the field of battle for health reasons but now, aged 29 and mum to a toddler, she’s being called up along with thousands of other reservists.

But what does that mean for her and her family?

“As the mother of a small child I can choose whether or not to be mobilised now.”

She continues, speaking softly and with utter conviction.

“But if this is going to be a large-scale war, with an attack on Kyiv, my family will move far away and I will stay here – to do whatever the army needs me to”