Poland has delivered the first Leopard 2 battle tanks to Ukraine, the Polish defence minister said on Friday, on the anniversary of Russia's invasion.

"Today Polish Leopards are already in Ukraine," Mariusz Blaszczak said during a National Security Council meeting, without elaborating on how many German-made tanks were delivered to Kyiv.

Poland was the first country to offer to send Leopards to Ukraine and was fiercely critical of Berlin's initial reluctance to approve the transfer of the powerful battle vehicles to Kyiv.

Also on Friday, Poland's Prime Minister Mateusz Morawiecki was visiting Kyiv, where he met with Ukrainian President Volodymyr Zelensky.

"On the anniversary of Russia's vicious attack on Ukraine, I am in Kyiv to give a clear signal of further support in defence of Ukraine," Morawiecki tweeted.

Poland has been one of Ukraine's staunchest supporters since Russia launched its full-scale invasion on February 24, 2022, urging its NATO and EU allies to ramp up military aid to the war-torn country.

Morawiecki also laid a wreath at the Fallen Defenders memorial in Kyiv alongside Ukrainian Prime Minister Denys Shmyhal.

Poland has stepped up its own arms purchases, raising its military budget this year to more than four percent of GDP. The country is also host to more than a million of Ukrainian refugees.

Earlier this week, Warsaw hosted US President Joe Biden who, following a surprise visit to Kyiv, met the leaders of nine countries on NATO's eastern flank in Poland.