"I think we could deliver at least one battalion in the first four months of this year. Three months maybe," he told reporters while on a visit to Warsaw.

"And then we have to proceed as fast as possible of course," he added, as the first anniversary of Russia's invasion of Ukraine looms.

Pistorius specified that he was talking about a "Ukrainian battalion, that means 31 tanks" and added subsequent battalions would follow later this year and next.

Germany recently gave the green light for Leopard battle tanks to be sent to Ukraine after a tireless campaign by Kyiv and allied countries.

It agreed to sent 14 Leopard 2 units from its own military stocks and also approved the reexport of the battle tanks to Ukraine by allies.

Poland has also pledged 14 tanks and Canada will send four, with Norway, Finland, Spain and Portugal indicating they will take part but with no specific numbers.

On Tuesday, Denmark, Germany and the Netherlands also promised that Ukraine would get at least 100 Leopard 1 tanks in the "coming months".

Earlier Wednesday, German Chancellor Olaf Scholz said it was clear that Russia would not win the war and assured Ukraine its future was in the EU.