Washington is encouraging Kyiv by publicly ignoring the drone attack that struck several districts of Moscow on Tuesday, Russia's envoy to the United States said on Wednesday, after President Vladimir Putin blamed Ukraine for the strikes.

The White House said it did not support attacks inside of Russia and that it was still gathering information on the incident, which Putin called an attempt to scare and provoke Moscow.

"What are these attempts to hide behind the phrase that they are 'gathering information'?" Anatoly Antonov, the ambassador, said in remarks published on the Telegram messaging channel.

"This is an encouragement for Ukrainian terrorists."

Putin on Tuesday cast the assault, which brought the 15-month war in Ukraine to the heart of Russia, as a terrorist act. Ukraine also accuses Russia of terrorism for its bombing of Ukrainian civilians, allegations Moscow denies.

A Ukrainian presidential aide denied Kyiv was directly involved in the drone attack on Moscow, but said Ukraine was enjoying watching events and forecast more to come.

The attack on Moscow, which injured two, came after Russia launched three air assaults within a day on Kyiv and 17 in May so far, killing two this month, sowing destruction and fear.

Russia has long accused what it calls the "collective West" of staging a proxy war against Moscow by supporting Ukraine with military and financial aid.

Russia launched a full-scale invasion of Ukraine in February 2022, devastating cities, forcing millions of people to flee their homes and costing thousands of lives.

Moscow calls the war a "special military operation" to "denazify" Ukraine and protect Russian speakers. Kyiv and its allies say it is an unprovoked land grab.