Ukraine said on Wednesday it carried out its largest long-range drone strike of the war on four Russian military airfields overnight, which were hailed by President Volodymyr Zelenskyy as "timely" and "accurate."

The General Staff said on Telegram that air bases "Khalino," "Savasleyka," "Borisoglebsk," and "Baltimor" in Voronezh, Kursk, and Nizhniy Novgorod regions were hit.

"The main targets were warehouses of fuel and lubricants and aviation weapons," it added, saying the results of the attack were being clarified.

A Kyiv security source said the strike aimed to undermine Moscow's ability to use warplanes for gliding bomb attacks on Ukraine.

Reuters could not independently verify the claim. Ukraine was still assessing the scale of damage, the source said.

"Thank you for the accurate, timely, and effective strikes on Russian airfields. Ukrainian drones work exactly as they should," Zelenskyy said as he addressed the military on Wednesday.

Russia's defense ministry said earlier that its air defenses had destroyed 117 drones and four tactical missiles launched by Ukraine at several regions including Kursk.

The strike on the airfields comes as Ukrainian troops are trying to press forward in Russia's Kursk region after they launched a surprise operation that has yielded their biggest battlefield gains since 2022.

Since the incursion last week, Russian forces have reduced the number of guided bomb attacks on border settlements in Ukraine's northeastern Kharkiv region, the local governor said on Monday.