As the Group of 7 leaders gathered Tuesday for a summit focusing in part on Russia’s war in Ukraine, President Volodymyr Zelensky said that Ukrainian drones had targeted an oil refinery in Moscow, about 10 miles from the Kremlin.

Moscow’s mayor, Sergei Sobyanin, said that the city had come under attack by dozens of drones, at least one of which struck the Moscow Oil Refinery. He said no one was killed or injured in the strike but did not discuss the extent of the damage.

A day earlier, Russia bombarded the Ukrainian capital, Kyiv, and other cities with missiles and drones that killed at least 11 people and injured dozens more. Some of Ukraine’s most cherished cultural institutions, including the Kyiv-Pechersk Lavra, one of the holiest cathedrals in the Eastern Orthodox Church, were damaged in the strikes.

In a video statement on Tuesday, Mr. Zelensky said of the Ukrainian drone attack: “This is a just response to Russian strikes and prolonging the war by the Kremlin.”

The Moscow Oil Refinery is in the Kapotnya district of the Russian capital and supplies more than a third of the city’s fuel demands, along with jet fuel and other petroleum products, according to industry publications.

As Mr. Zelensky has pressed for direct talks with President Vladimir V. Putin of Russia to negotiate an end to the war, the Ukrainian military has stepped up its campaign to raise the costs of the war for the Kremlin by targeting oil and gas facilities inside Russia.

Speaking to reporters after meeting with President Trump at the summit, Mr. Zelensky said he had emphasized his nation’s need for air defense missiles capable of countering the Kremlin’s arsenal of ballistic missiles.

“I also raised this issue in my discussion with President Trump, and our teams will continue working on it,” he said.

More civilians were killed and injured in Ukraine in May than in any month since the spring of 2022, according to the United Nations, which reported at least 274 deaths and nearly 1,800 injured.

Four years of Russian attacks have also devastated the Ukrainian energy grid, prompting fears of a humanitarian crisis if the war grinds into another brutal winter.

“If the war has not ended by winter and shortages arise, all partners pledged to support Ukraine with supplies of diesel fuel, natural gas, and gasoline,” Mr. Zelensky said.