WARSAW - Russia has halted supplies of oil to Poland via the Druzhba pipeline, PKN Orlen's CEO said on Saturday, adding that the Polish refiner would tap other sources to plug the gap.

The halt in supplies via the pipeline - which has been exempted from European Union sanctions imposed on Russia following its full-scale invasion of Ukraine - came a day after Poland delivered its first Leopard tanks to Ukraine.

"Russia has halted supplies to Poland, for which we are prepared. Only 10% of crude oil has been coming from Russia and we will replace it with oil from other sources," PKN Orlen Chief Executive Daniel Obajtek wrote on Twitter.

Orlen said it could fully supply its refineries via sea and that the halt in pipeline supplies would not impact deliveries of gasoline and diesel to its customers.

As of February, after a contract with Russia's Rosneft expired, Orlen has been getting oil under a deal with Russian oil and natural gas company Tatneft.

Tatneft and Russian oil pipeline monopoly Transneft did not immediately respond to a request for comment.

Oil transport to the Czech Republic, where Orlen operates two refineries, via the southern branch of the Druzhba pipeline was running to plan, pipeline operator Mero said on Saturday.

The supply halt came after U.S. President Joe Biden visited Warsaw and Kyiv in a show of support for Ukraine a year after the invasion. And on Friday, the European Union agreed on a 10th package of sanctions on Russia.

Following the invasion of Ukraine and before the EU embargoed seaborne supplies from Russia, Orlen stopped buying Russian oil and fuels transported by sea.

It said its supply portfolio now includes oil from Western Africa, the Mediterranean, the Gulf and the Gulf of Mexico. It also has a supply contract with Saudi Aramco as of 2022.

Seaborne supplies reach Poland via Naftoport, an oil terminal in Gdansk on the Baltic Sea. It can receive 36 million tonnes of oil annually topping volumes that can be processed by Polish refineries and is in part used to supply oil to refineries in eastern Germany that are linked to Druzhba. "Given the capacity of Naftoport and the fact that we also have other routes to import motor fuels, clients will not feel any impact, while Orlen has been prepared for this for months," Mateusz Berger, Poland's Secretary of State in charge of strategic energy infrastructure told Reuters by telephone.

(Reporting by Marek Strzelecki; Additional reporting by Jason Hovet; Editing by Helen Popper, Frank Jack Daniel and Alexander Smith)