The Druzhba pipeline, which transports oil from Russia to Poland, has been shut down, according to the chief executive of Polish refiner PKN Orlen, who also added that the business would look to alternative sources to fill the gap.

Following Poland’s delivery of its first Leopard tanks to Ukraine, shipments via the pipeline, which had been immune from EU sanctions placed on Russia as a result of its full-scale invasion of Ukraine, were stopped.

“We’re effectively securing supplies. 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.

The company 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 clients.

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

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

The supply halt came after U.S. President Joe Biden visited Warsaw and Kyiv this week in a show of support for Ukraine a year after the invasion.

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 via the sea.

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

Through Naftoport, an oil terminal in Gdansk on the Baltic Sea, seaborne supplies are delivered to Poland. It can receive 36 million tonnes of oil per year, which is more than Polish refineries can process, and it is utilized in part to supply oil to Druzhba-connected refineries in eastern Germany.

Clients won’t see any effects because of Naftoport’s capacity and the availability of alternative channels for importing motor fuels, according to Mateusz Berger, Secretary of State in charge of strategic energy infrastructure, who spoke with Reuters via phone.