Saudi Arabia has become Europe's largest supplier of crude oil as the country sells its own supplies to the EU while bolstering its reserves by importing sanctioned Russian oil, a Bloomberg report published on Thursday shows.

The Gulf country reportedly purchased around 174,000 barrels per day of diesel and gasoil in the month of April and imports increased in May, according to Bloomberg.

Saudi imports of Russian petroleum are at their highest levels since 2017 according to the data available from Vortexa Ltd. and Kpler, two shipping analytics firms.

Kpler has also said that Riyadh has surpassed the US in diesel and gasoil exports to become the global leader in the market.

In April, 35% of the Kingdom's fuel exports from the Jubail and Yanbu ports went to the EU and the UK as Saudi Arabia has been able to curb sanctions on the Russian energy sector by supplying Western countries with its own product while recycling Russian oil into domestic use or other markets.

However, a recent report by the Wall Street Journal shows that tensions between Russia and Saudi Arabia are on the rise, as Moscow is reportedly unwilling to further cut oil production to meet the $80+ Brent pricing, the international oil contract, that Saudi Arabia is looking to reach.

WSJ added that "Saudi officials have complained to senior Russian officials and asked them to respect the agreed cuts."

The report says that frictions "between the world's two biggest oil producers ahead of a crucial meeting between members of" OPEC+ are "very apparent" as the sides are set to meet in Vienna on June 4.

The report pointed to recent data that shows Russia upscaling of production which has pushed oil prices down as Saudi began to implement production cuts this month.

Oil prices have decreased by around 10% since early April after members of OPEC+ agreed to reduce oil output for the month. On Friday, Brent registered a rise of 0.9% to $76.95.

The hike in oil prices comes amid uncertainties about the next move to be taken by OPEC+ after ministers raised market uncertainties ahead of the upcoming meeting for the organization.

WSJ's report says that Riyadh is "under pressure to maintain higher oil prices with its budget requiring an estimated $81 a barrel" to meet expenditures.

The country has undertaken "massive development projects" which have been described as "gigaprojects" that have pushed Riyadh to increase oil income to fund its spending which has been estimated to cost hundreds of billion of US dollars.