Hungary and Slovakia threatened to take Ukraine to court for blocking Russian producer Lukoil's oil from passing through the Druzhba (Friendship) pipeline - the last route for Russian crude oil to reach Europe.
Hungary and Slovakia, along with the Czech Republic, are three member states exempt from the EU's embargo on Russian oil because they depend on this supply and have few alternatives.
As a result, Russia continues to transport about 300,000 barrels of oil per day - equivalent to about 0.3% of global supply - to Eastern Europe via the southern branch of the Druzhba.
The southern Druzhba line connects Russian oil fields with the refineries of the MOL company in Hungary and Slovakia, PKN Orlen in the Czech Republic.
This oil pipeline passes through Belarus and Ukraine before branching out to Slovakia and Hungary.
According to Reuters, oil exports through the Druzhba pipeline were suspended several times last year due to complicated relationships between suppliers, pipeline companies and buyers.
In 2022, oil supplies stopped briefly due to sanctions that left Russian company Transneft unable to pay shipping fees.
Ukrainian supplier Ukrtransnafta has increased oil transportation fees several times in 2022 and 2023.
Sources in the Russian oil and gas industry say higher fees make the Druzhba pipeline one of the least profitable routes.
Private oil company Lukoil supplies about 50% of the oil transported to the southern Druzhba route. In June 2024, Ukraine imposed sanctions on Lukoil, making it impossible for the company to transport oil through this pipeline.
Hungary and Slovakia are landlocked countries, leading to limited access to alternative oil sources. This was also acknowledged by Hungarian Foreign Minister Peter Szijjarto.
"To buy oil or gas from different sources, there needs to be pipelines, already built infrastructure. If there is none and no one helps us get that infrastructure, we cannot get freedom like diversifying supply sources" - Foreign Minister Szijjarto said.
Reuters pointed out that in addition to the oil pipeline through Ukraine, Hungary can import oil from Omisalj port in Croatia. Since April, MOL has imported about 500,000 tons of oil per month (120,000 barrels/day) through Croatia.
And after Ukraine blocked Russia's oil pipeline , Hungarian Foreign Minister Peter Szijjarto informed that Bulgaria offered to support Hungary's oil supply.
"My Bulgarian colleague (Foreign Minister Dimitar Glavchev - Reporter) has offered to help overcome difficulties related to the ban on oil transportation through Ukraine," Mr. Szijjarto revealed.
"As a true friend and a reliable transit country, Bulgaria facilitates the security of Hungary's energy supply. Last year, 5.6 billion m3 of gas was supplied to Hungary via Bulgaria . This year, we bought 3.9 billion m3 of gas" - Hungary's Foreign Minister noted.
Meanwhile, Slovakia can only import oil through the oil pipeline connected to Hungary, with the imported volume not enough to compensate for Russian oil.
About 30% of the oil that Slovnaft - the MOL-owned refinery in Slovakia - processed in 2023 was non-Russian oil, the highest level ever.
Ukraine also depends on Hungary and Slovakia for energy. These two countries supply fuel and electricity produced from Russian resources to Ukraine. Hungary provided 42% of Ukraine's imported electricity in June 2024.
