U.S. President Donald Trump said he got “very angry” after Ukraine damaged a Russian oil pipeline that supplies his friend Viktor Orbán, Hungary’s prime minister.

Trump responded to a note from Orbán, who complained about a Ukrainian drone attack overnight on Aug. 13 hitting the Druzhba oil pipeline, which supplies Hungary, Slovakia and other countries in Central Europe with Russian oil through Ukrainian territory.

“Viktor — I do not like hearing this. I am very angry about it. Tell Slovakia,” Trump wrote according to a letter published online by Orbán’s ruling Fidesz party. “You are my great friend,” the U.S. president added.

In his note, Orbán wrote that “just before the historic meeting between President Trump and [Russian President Vladimir] Putin in Alaska,” Ukraine carried out drone strikes on the Druzhba oil pipeline in Russian territory.

The pipeline, which was restored by Aug. 19, was hit again two days later. 

Notably, both strikes were carried out by the Unmanned Systems Forces of Ukraine, led by Commander Robert Brovdi, who is also commonly known by his call sign “Madyar,” referring to his Hungarian ethnicity. 

Brovdi announced his second strike on Telegram with the Hungarian battle cry, “Ruszkik haza!” The phrase means “Russians go home” — a reference to the slogan of Hungarian freedom fighters who confronted the Soviet army in 1956.

Orbán — who has maintained close ties with the Kremlin even after it launched its full-scale invasion of Ukraine in 2022 — did not take the message well.

“Hungary supports Ukraine with electricity and petrol, in return they bomb pipeline that supply us. Very unfriendly move,” he wrote in his missive to Trump.

Since Budapest received a temporary exemption from the European Union’s ban on Russian oil, it has increased its purchases of crude via the overland pipeline network, making major profits from discounted crude.

Hungary has repeatedly threatened to veto any EU efforts to further reduce its dependency on Russian energy.