British-supplied Challenger 2 main battle tanks will soon begin combat missions in Ukraine, the country's defence minister has said.
Oleksii Reznikov said the "fantastic machines" have "recently arrived" in Ukraine.
The UK promised 14 of the vehicles to Ukraine, a move which helped persuade other Western nations to supply their own tanks to the country to aid the fight against the Russian invasion.
Ukraine's defence minister was all 'thumbs-up' in a video on social media showing him taking one of the Challenger 2s "for a spin".
Mr Reznikov thanked Prime Minister Rishi Sunak and Defence Secretary Ben Wallace and called it a "pleasure" to be in the Challenger 2, adding: "These fantastic machines will soon begin their combat missions."
The video and a photo posted online show vehicles including the Cougar MRAP, other Challenger 2s, US-supplied Strykers, and the German-supplied Marder infantry fighting vehicle.
Major General Maxim 'Mike' Mirgorodsky, Commander of the Airborne Assault Forces of Ukraine, is also in the photo, the post says.
With the Challenger 2, Russia will be fighting an undefeated platform – not once has it been destroyed at the hands of an enemy.
'They have arrived!'
The Ukrainian MOD could also not hide its delight at the arrival of the land vehicles.
"Strykers and Cougars from the US, Challengers from the UK, Marders from Germany have officially joined the Air Assault Forces of the #UAarmy! The greatest vehicles for the best soldiers. Onward!" a Twitter post said.
The German defence ministry has also revealed that the first shipment of Leopard 2 tanks from Germany has been sent to Ukraine.
Defence Minister Boris Pistorius said he was sure the tanks could "make a decisive contribution" on the frontlines of the war.
Ukrainian tank crews trained in the UK on the Challenger 2s, which are being donated along with ammunition and spares, and have now returned home.
The Ministry of Defence (MOD) said that the training had been completed after UK military officials spent several weeks instructing Ukrainian personnel how to operate and fight with the tanks.
Mr Wallace said the Ukrainian soldiers "return to their homeland better equipped, but to no less danger".
The Defence Secretary, who visited the Ukrainian troops during their training at Bovington Camp in Dorset in February, said: "It is truly inspiring to witness the determination of Ukrainian soldiers having completed their training on British Challenger 2 tanks on British soil."
Russia condemned the UK's move and predicted the tanks would "burn" on the battlefields of Ukraine.
Russian president Vladimir Putin has also reacted to the UK's decision to supply depleted uranium armour-piercing rounds for the tanks in Ukraine by announcing plans to station tactical nuclear weapons in neighbouring Belarus.
Former tank commander Hamish de Bretton-Gordon OBE has questioned the standard of Russia's armoured vehicles, believing that Mr Putin and his generals have already lost if all they can do now is send pre-Second World War T34 tanks and 1950s T55 tanks to the frontline.