Ukrainian President Volodymyr Zelenskyy said Ukraine will step up attacks on Russian oil refineries in response to what he called a "new doctrine" of Russian airstrikes aimed at forcing people out of Kyiv and other cities.
Russia's Defense Ministry responded that it would intensify its strikes.
"With their attacks on our energy, we have to respond on their energy. First of all, oil refiners etc: what gives money to them for this war," Zelenskyy told Reuters in an interview Saturday.
"But we will not respond, of course, just like them, on any civilian objects," he added.
Ukraine's drone strikes on Russian refineries have contributed to record global diesel prices, prompting U.S. President Donald Trump to urge Kyiv last month to stop hitting Russian oil facilities.
The escalation comes as Ankara, Washington, and other mediator countries seek to revive peace talks.
Zelenskyy said Ukrainian intelligence had obtained documents showing Russian President Vladimir Putin issued a "new doctrine" of attacks on a much broader range of civilian targets ahead of winter.
"We saw documents and we know that they allow them to attack infrastructure, logistics, and especially to attack in the cities, in the villages, everywhere, roads, schools, hospitals," he said, adding, "To pressure people to leave the capital, leave different cities: this is the goal of the operation."
Over the past week, Russia has struck energy, telecommunications, road and rail infrastructure in Kyiv and, for the first time, bridges across the Dnipro River.
Both sides deny deliberately targeting civilians.
"Following Zelenskyy's statement... strikes by the Armed Forces of the Russian Federation on military and military-industrial facilities, as well as related infrastructure in Kyiv and other regions of Ukraine, will be intensified," Russia's Defense Ministry said.
Kremlin spokesman Dmitry Peskov on Monday accused Kyiv of expanding attacks on Russia's "civilian economy."
"What our armed forces are doing now is exacting retribution for that. Ukraine must, and certainly will, pay the price for these actions," he said.
On foreign missions that remain in Kyiv despite Moscow's warnings, Peskov said: "The decision rests with the countries that maintain diplomatic missions in Kyiv. Our military continues its work."
Putin said last week that Ukrainian strikes on refineries had cost Russia about 1% of its gross domestic product (GDP).
The G7 agreed last week to release 100 million barrels from emergency reserves, with diesel front-loaded, as prices hit records amid the Iran war and Russia's diesel export ban.
Zelenskyy said Sunday that Washington is proposing a technical-level trilateral meeting with Ukraine and Russia by the end of October.
"I confirmed to them that our side is ready to support this timeline," he said, adding that Ukraine was open to the UAE or another venue.
He urged the U.S. not to normalize ties with Moscow before peace is secured. "It's not fair just to normalise," Zelenskyy said, adding, "Peace is more important than any kind of economy."
"President Trump wants to have some kind of victory before the midterms. But Putin will do everything to push the Iranians and make this whole situation non-negotiable," Zelenskyy said.
Asked about a New York Times (NYT) report linking a sale of Lukoil's foreign assets to U.S.-Russia talks, Peskov said only that "the topic of potential interaction and cooperation in the energy sector does indeed come up during conversations with our American counterparts."