The construction worker, who declines to give his full name, was at home in France when Russia invaded its neighbour on February 24.

What he saw on his TV screen made him so angry, he says, he decided to set off for Ukraine the very next day.

"I couldn't just sit on my settee and watch what was going on," he tells AFP.

It took him 10 days, by car and train, to reach Ukraine.

At the border, local troops directed him to the Georgian foreign legion, a military unit set up in 2014 by former soldiers from the Caucasus to help Kyiv fight Moscow.

Now Pierre is cooling his heels in Kyiv, waiting to be posted somewhere. It'll probably be near the capital, a city he doesn't know, and which Russian forces are trying to encircle.

He hopes to be deployed "where I'll be most useful -- on the front line" so he can use the skills he picked up in Syria, like "firing 12.7 mms and 14.5 mms (machine guns), Kalashnikovs and rocket launchers".

- 'To the very end' -

Brown-haired, lean, of middling height, Pierre strolls calmly into the discrete park in Kyiv where he has agreed to talk to AFP.

He is dressed in beige sneakers and a military-style khaki sweatshirt, with a khaki scarf hiding half his face.

He is one of a string of foreigners to respond to President Volodymyr Zelensky's appeal for volunteers to come and repel the Russian forces.

The Ukrainian government puts their number at 20,000, though that figure has not been independently verified.

Pierre expects to be in for the long haul.

"I'll stick around right until the end of the war if need be," he says, out of a sense of "commitment" and "solidarity" with Ukrainians who are "fighting for their freedom against the Russian oppressor".

In Syria, Pierre says, he fought other "oppressors" -- Islamic State (IS) group jihadists and Turkish forces battling the Syrian Kurds.

Between 2014 and 2010, Pierre says he spent a total of four years fighting in Syria, in three separate stints.

He reels off the names of northern Syria's ferocious battles -- "Manbij, Raqa, Deir Ezzor" -- and says he came close to death there on more than one occasion.

Raqa, former "capital" of the IS group's self-declared caliphate, was the worst, he recalls.

When Kurdish forces backed by NATO air power retook Raqa in 2017, the retreating IS fighters mined entire neighbourhoods.

Pierre says he and his unit were searching a building when one of his comrades stepped on a mine hidden under debris in a staircase.

Pierre was in a sheltered corner of the stairwell and escaped unharmed. But he saw four men die in front of his eyes.

"It shakes you up a bit," he acknowledges.

- 'A political football' -

According to one inside source, the Georgian foreign legion in Ukraine comprises between several dozen and several hundred foreign fighters.

As in Syria, Pierre says volunteers combatants are joining from all over -- "Italians, Germans, Norwegians, Spaniards, people from pretty much everywhere in Europe. Even from India."

Pierre admires the Ukrainians for their courage and unity.

"Every single civilian is prepared to fight," he says, forgetting that in Kyiv alone, half the city's population is estimated to have left since the start of the invasion.

He sees Ukraine as "a political football" in a high-stakes game between Russia and the United States.

"At the end, it's the Ukrainians who end up in the shit," he says contemptuously.

"When all hell lets loose, there's no-one there to help them. Other countries just fall over themselves to send in weapons."

He says France is just as "hypocritical" as the other European nations, making outraged noises but "letting massacres happen" in Ukraine, just like in "Kurdistan, Yemen and Myanmar".

When he was younger, Pierre wanted to join the French army. But he "did a few stupid things", he explains without going into details, and that was no longer an option.

He knows his long stints in Syria look suspicious to the French authorities and they won't help prise open any barracks gates on his behalf.

But now he says he is grateful he was prevented from going into the forces. "It's better to go to Kurdistan or here (in Ukraine) on your own than play the politicians' hypocritical game."