Poland will send more tanks to Ukraine "in a few days", Prime Minister Mateusz Morawiecki said in Kyiv on Friday after Warsaw announced the despatch of four Leopard 2 tanks.

"We were able to transfer our tanks very soon...  also in a few days we are delivering very good PT-91 tanks -- 60 tanks will come to Ukraine," Morawiecki told reporters.

Poland's head of government spoke following talks with Ukrainian President Volodymyr Zelensky in Kyiv on the anniversary of Russia's invasion.

"I came here today not only to offer words of support but also with the knowledge that we must respond with force to this barbarian aggression," Morawiecki told reporters.

Polish Defence Minister Mariusz Blaszczak had earlier announced that "today Polish Leopards are already in Ukraine".

Morawiecki specified that his country had already delivered four of the German-made tanks.

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.

Morawiecki also said in Kyiv that Warsaw was prepared to train Ukrainians on F-16 fighter jets in Poland.

"I underline that this should always be agreed within the broader coalition, but Poland is ready to carry out such training," he told reporters.

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 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.