Ukraine has stepped up long-range drone attacks on Russian territory, striking the Novokuibyshevsk and Ryazan oil refineries over the weekend. Industry sources say the Ryazan plant, located about 200 kilometres southeast of Moscow, has been forced to cut throughput by roughly 50% since 2 August after sustaining damage in a drone strike late last month. The facility can process around 310,000 barrels of crude a day, while the Novokuibyshevsk refinery in the Samara region has a capacity of about 160,000 barrels a day. In a separate operation, Ukraine’s Security Service said its drones hit the Saki military airfield in Russian-occupied Crimea overnight, destroying one fighter jet and damaging four others. Kyiv described the raid as part of a broader effort to weaken Russia’s air power on the Black Sea front. The uptick in attacks comes as diplomatic pressure mounts ahead of U.S. President Donald Trump’s 8 August deadline for the Kremlin to accept a cease-fire or face additional tariffs and sanctions. Kremlin spokesman Dmitry Peskov called Washington’s mediation efforts “very crucial,” and Trump’s special envoy, Steve Witkoff, is expected in Moscow later this week for talks.