The Kremlin said on Wednesday it did not believe a statement by Ukrainian presidential adviser Mykhailo Podolyak that Ukraine does not launch attacks against targets on Russian territory.
Kremlin spokesman Dmitry Peskov was speaking a day after Russian officials blamed Ukraine for several attempted drone strikes, the latest of many inside Russian territory for which Ukraine has not publicly claimed responsibility.
Podolyak said in a tweet earlier on Wednesday that Ukraine "doesn't strike at RF's (Russian Federation's) territory" and "is waging a defensive war to deoccupy all its territories".
He added: "Panic & disintegration processes are building up in RF, reflected by an increase in internal attacks on infrastructure facilities by unidentified flying objects." His comment prompted a string of jokes on Twitter about alien activity.
Asked about Podolyak's denial of Ukrainian attacks, Peskov said: "We don't believe him."
On Tuesday, a drone crashed near a natural gas pumping station southeast of Moscow in an apparent failed attack 110 km (68 miles) from the center of the Russian capital, the regional governor said.
The defense ministry said on Wednesday its forces had repelled what it described as a massive drone attack on Crimea, which Moscow annexed from Ukraine in 2014, a day after accusing Kyiv of launching failed drone attacks on two southern Russian regions.
In December, Russia said six of its military personnel were killed in what it said were Ukrainian drone attacks on air bases deep inside Russian territory, including one base where Russian strategic nuclear bombers are stationed.