Russia attacked the Ukrainian power grid on the night of Saturday/Sunday as part of its ongoing campaign to weaken Ukraine’s energy infrastructure ahead of winter.

The attack came as Moscow expressed “deep concern” over the possibility of the United States supplying Ukraine with “Tomahawk” missiles.

The governor of Kyiv region, Mykola Klashnyk, said two employees of DTEK, Ukraine’s largest private energy company, were injured in Russian attacks targeting a substation in the area.

The Ukrainian Ministry of Energy reported that energy infrastructure was also attacked in the Donetsk, Odessa, and Chernihiv regions.

Ukrainian President Volodymyr Zelensky said via the social media platform X that “Russia continues its air assault on our cities and communities, intensifying its strikes on our energy infrastructure.”

Zelensky added that Russia launched “more than 3,100 drones, 92 missiles, and about 1,360 glide bombs” on Ukraine during the past week.

He also called for tightening secondary sanctions on Russian oil buyers.

Zelensky said, “Sanctions, tariffs, and joint measures against Russian oil buyers, those who finance this war, must remain on the table.”

On Sunday, he wrote that he had a “very productive” phone call with U.S. President Donald Trump, discussing strengthening Ukraine’s “air defense, resilience, and long-range capabilities,” as well as “details related to the energy sector.”

Zelensky said their discussion followed a previous conversation on Saturday, during which the two presidents agreed on the topics for Sunday.

The calls came after Zelensky said on Friday he was in talks with U.S. officials about a possible provision of weapons for precise long-range strikes, including “Tomahawk” missiles and more tactical ballistic missiles “ATACMS.”

Trump, frustrated with Russia regarding his efforts to end the war, said earlier this week he had “made a decision” about sending “Tomahawk” missiles to Ukraine, without providing details. A high-level Ukrainian delegation is visiting the United States this week.

Meanwhile, Kremlin spokesman Dmitry Peskov said in comments published Sunday that “the Tomahawk issue is a matter of great concern.”

He told Russian state TV journalist Pavel Zarubin: “This is indeed a very tense moment concerning the fact that tensions are escalating from all sides.”