Germany has dispatched 18 Leopard battle tanks to Ukraine as promised earlier, a report said Monday, helping Kyiv to fight back against Russia with much-needed heavy weaponry.

The last of the tanks left Germany at the end of last week and have been handed over to Ukraine at the border, news outlet Spiegel reported.

About 40 Marder infantry fighting vehicles have also arrived in Ukraine, it said, adding Berlin was keeping the route of the deliveries secret for security reasons.

The German defense ministry declined to comment when contacted by Agence France-Presse (AFP).

Ukrainian soldiers were trained on the 2A6s, the most advanced of the Leopard models, on German military bases.

At the end of January, Berlin finally gave the green light for German-made Leopards – among the world's most advanced tanks and used by militaries across Europe – to be sent to Ukraine.

Under German law, any country wanting to send the tanks to another country must first get approval from Berlin.

The government of Chancellor Olaf Scholz initially said it was aiming to assemble, along with allies, two battalions of tanks for Kyiv—about 60 tanks in total.

But they have since struggled to get the numbers together.