Ukraine’s air force said 84 of 99 targets were shot down, but Prime Minister Denys Shmyhal, posting on social media, said the Russian strikes damaged energy assets in six regions. In some areas, that required emergency shutdowns.

For months, Ukrainian officials had been pleading with their Western counterparts for more air defenses, warning that Russia was likely to step up its aerial attacks. Last year, Moscow targeted Ukraine’s energy grid all winter, but those attacks became less effective after Kyiv received better air-defense systems, such as the U.S.-designed Patriot.

Now, with resources dwindling in Ukraine amid the Republican blockage of a $60 billion aid package proposed by the Biden administration, Moscow appears to be capitalizing on a moment of weakness.

Thursday’s attack followed a similar strike a week ago that caused rolling blackouts in Ukraine’s northeastern Kharkiv region. Power still has not been fully restored in that area. Ukrainian Energy Minister German Galushchenko called that “the largest attack on the Ukrainian energy sector in recent times.”

Zelensky said Thursday he spoke with House Speaker Mike Johnson (R-La.), who for the last month has blocked a vote on the aid package. Johnson refused to include it in a major spending measure that Congress adopted earlier this month to keep the U.S. government financed through the remainder of the fiscal year.

Zelensky, posting on social media, said he briefed Johnson “on the battlefield situation, specifically the dramatic increase in Russia’s air terror.”

“In this situation, quick passage of U.S. aid to Ukraine by Congress is vital,” Zelensky said in a post on X, formerly Twitter. “We recognize that there are differing views in the House of Representatives on how to proceed, but the key is to keep the issue of aid to Ukraine as a unifying factor.”

Anastacia Galouchka contributed to this report.