Putin said on Tuesday that the missile strike on Ukraine’s spy agency provoked the uncommon drone assault on Moscow.

Putin blamed Ukraine for “terrorist acts” and “provoking us to take reciprocal actions” on Russian state TV after the drone hit residential zones in Moscow early on Tuesday morning, which he said were aimed at “intimidating Russian citizens by targeting residential buildings.”

“He said a (Ukrainian) military intelligence base was hit a few days ago.”

“The Kyiv regime opted for a different way to scare Russians,” he continued, referring to the earlier attack on Moscow.

He also promised to strike back, which raised concerns in the West that Russia might use this as an excuse for its own nuclear use.

Putin said Moscow’s anti-air defenses were “adequate” but said that “there is still room for improvement”, noting that Russia had faced similar issues at Hmeimim air base during its intervention in support of Bashar al-Assad’s regime in the Syrian war.

A day after Russia bombarded Kyiv with aerial strikes, killing at least one person— the fourth assault on Ukraine’s capital in three days, the drone attack on Moscow occurred.

On Tuesday, Russia said that it shot down all eight of the Ukrainian drones aimed at Moscow and blamed Kyiv for a “terrorist assault”. There were no reports of fatalities, but authorities said that the early morning assault wounded two people, one of whom was taken to hospital.

Ukrainian presidential aide Mykhailo Podolyak rejected Kyiv’s role in the attack, but Moscow has opened an investigation into the incident as Russian forensic experts were seen in the capital, gathering what looks like pieces of a drone.

US doesn’t endorse attacks inside Russia The United States on Tuesday said that it doesn’t endorse attacks in Moscow, but added that Russia was accountable for the war with Ukraine.

“We do not support attacks inside of Russia in general. We have been focused on providing Ukraine with the equipment and training they need to reclaim their own sovereign territory,” a State Department spokesperson said.

The spokesperson added that the United States was still evaluating what happened in Moscow, where residential buildings were hit for the first time since Russia invaded Ukraine. President Vladimir Putin accused Kyiv.