The Russian military shot down 31 Ukrainian drones during overnight raids across the country, the Russian Defense Ministry said Wednesday.

The drone attack appeared to be the largest single drone assault on Russia since the beginning of the war over a year-and-a-half ago, The Associated Press reported. There were no reports of damage or casualties from the attempted strikes.

The Russian military claimed in a post on Telegram that the strikes were targeted to the border regions of Belgorod, Bryansk and Kursk. 

The alleged failed attack comes as the Ukrainian military continues its slow counteroffensive against the Russian forces in the east of the country. Their slow advance and dwindling resources have garnered criticism from Western allies, as winter quickly approaches and is expected to slow fighting.

National Security Council spokesperson John Kirby emphasized the importance of continuing military aid for Ukraine on Tuesday as the issue remains front-and-center in budget negotiations.

“It is imperative that we help them take advantage of every single day,” Kirby told reporters Tuesday. “A lapse in support for even a short period of time can make all the difference on the battlefield, just as creating such a lapse in support will make [Russian President Vladimir Putin] believe he can wait us out and that he can continue the conflict until we and our allies and partners fold.”

Support for Ukraine abroad has also faltered in recent months, as a pro-Russia party in NATO member Slovenia was elected this week.

“I see no tragedy, but room for intense work and strengthening our positions,” one Ukrainian official told The Hill regarding U.S. support.

The Russian military also claimed it thwarted an amphibious assault in western Crimea, stopping a group of Ukrainian soldiers from landing at Cape Tarkhankut, Crimea, on a high-speed military boat and jet skis.

In other updates early Wednesday, the officials claimed Russia had killed more than 400 Ukrainian soldiers and numerous pieces of equipment in artillery strikes aimed at halting the Ukrainian advance.

Moscow’s claims could not be independently verified, and Ukrainian officials made no immediate comment, the AP reported.