President Volodymyr Zelenskyy said Ukraine will double down on attacking Russian oil refineries, in a Reuters interview published on Saturday.

Zelenskyy said Ukrainian intelligence obtained documents showing Russian President Vladimir Putin issued a new doctrine of broader airstrikes aimed at forcing residents to leave Kyiv and other cities. He said Russia planned attacks on infrastructure, roads, schools and hospitals.

“We have to respond in any way we can,” Zelenskyy told Reuters. “With their attacks on our energy, we have to respond on their energy.” He stressed Ukraine would not deliberately target civilians.

Russia said it would intensify strikes on Ukrainian military and defence industry targets in response to the interview. The defence ministry said recent strikes were retaliation for Ukrainian attacks.

Both sides deny deliberately hitting civilians. Russia recently hit bridges across the Dnipro river, disrupting life in Kyiv for its three million residents ahead of winter.

The United States under President Donald Trump has meanwhile been trying to revive talks to end the four-year-old war, Europe’s bloodiest since 1945.