Ukraine has stepped up drone attacks on Russian oil refineries and exporting infrastructure, striking the most important sector of President Vladimir Putin’s economy to show it can fight back as the United States seeks to broker a peace deal.

The attacks disrupted Moscow’s oil processing and exports, created gasoline shortages in some parts of Russia and came in response to Moscow’s advances on the front lines and its pounding of Ukraine’s gas and power facilities.

Kyiv’s move is an attempt to raise the stakes in possible peace talks and challenge the idea that Ukraine has already lost the war after US President Donald Trump and Putin met in Alaska this month, analysts have said.

Ukrainian attacks on 10 plants disrupted at least 17% of Russia’s refinery capacity, or 1.1 million barrels per day, according to Reuters calculations.

The drone war has pushed more crude towards exports from the world’s No.2 oil exporter at a time when Washington is pressing China and India to reduce purchases of Russian oil.

The refinery hits come as Russia’s seasonal demand for gasoline from tourists and farmers peaks. Russia had tightened its gasoline export ban in July to deal with a spike in domestic demand even before the attacks.

There were shortages of gasoline in some areas of Russian-controlled Ukraine, southern Russia and even the Far East, forcing motorists to switch to more expensive petrol due to shortages of the regular A-95 grade.

“We will endure, but this is a big hit to our family budget, a big hit. It’s really noticeable,” said Svetlana Bazhanova, a resident of Sevastopol, the largest city in Crimea, which Russia annexed in 2014.