The NATO chief has urged other countries to prepare their armoured vehicles.
Poland has sent an official request to Germany for permission to transfer Leopard 2 tanks to the Ukrainian Armed Forces.
Polish Defence Minister Mariusz Blaszczak said this on Twitter.
"The Germans have already received our request for consent to transfer Leopard 2 tanks to Ukraine. I also ask the German side to join the coalition of countries supporting Ukraine with Leopard 2 tanks. This is our common cause, after all, it is about the security of the whole of Europe!" Blaszczak wrote.
NATO Secretary-General Jens Stoltenberg also said that Berlin's permission to supply Ukraine with Leopard 2 tanks "is coming soon", so the countries that have this equipment in their arms and plan to hand it over can already prepare for it.