Training of Ukrainian troops on German Marder infantry fighting vehicles will start in the next few days, he added, "and for the Ukrainian soldiers who will be trained on the Leopard it will be a little later".

Berlin finally agreed to deliver the powerful German-made Leopard tanks on Wednesday after weeks of intense pressure from Kyiv and many of its European allies.

Germany will provide 14 Leopard 2 A6 tanks from its Bundeswehr supplies, Chancellor Olaf Scholz told the German parliament.

It is also granting approval for other European countries to send the German-made tanks from their own stocks to Ukraine, with the aim of quickly assembling "two tank battalions with Leopard 2 tanks for Ukraine", Scholz said.

The Leopard 2 is seen as one of the best-performing tank models worldwide and is widely used across Europe, meaning spare parts and ammunition can be easily obtained.

The United States later also said it would send 31 Abrams tanks, one of the most powerful and sophisticated weapons in the US army.

Although Western countries have already sent Ukraine everything from artillery to Patriot anti-missile defence systems, tanks were long considered a step too far, risking a widening backlash from Russia.

On Thursday, Kremlin spokesman Dmitry Peskov warned that Russia viewed the tank deliveries as "direct involvement in the conflict".

But with Ukraine gearing up for a counteroffensive to push back increasingly entrenched Russians in the east and south, the allies are now scrambling to send the powerful weapon.

Pistorius, who was appointed as German defence minister only last week, was speaking during a visit to German troops in the state of Saxony-Anhalt.