Russia and Ukraine continued to trade barbs Tuesday over an alleged drone attack on one of Russian President Vladimir Putin’s official residences.

Ukraine has denied it carried out any such strike, describing it as a “complete fabrication,” but the Kremlin said that its military stands ready to retaliate.

Russia’s Foreign Minister Sergei Lavrov on Monday alleged that Ukraine had fired 91 drones at Putin’s official residence in the Novgorod region, located between Moscow and St Petersburg.

Lavrov said the drones, allegedly launched between Sunday night and Monday morning, had been destroyed by air defenses and that no casualties had been reported. It’s not clear where Putin was at the time of the alleged incident, and Lavrov provided no further details.

Ukraine denied the claims and instead accused Moscow of trying to undermine peace talks.