Ukraine’s top military intelligence official said on Wednesday that Russia’s military offensive was slowing because of moral and physical fatigue in their ranks and Moscow’s “exhausted” resource base.

The remark on television by Defence Intelligence agency chief Kyrylo Budanov was one of the strongest signals by Kyiv that it believes Russia’s offensive power may be waning.

“Russia has rather seriously slowed down the tempo of its assault. The reason for this is the exhaustion of their resource base, as well as a moral and physical fatigue from the fighting,” he said.

Russian Defence Minister Sergei Shoigu said earlier that Moscow had deliberately slowed down its campaign in Ukraine, something he said had been driven by the need to reduce civilian casualties.

Russia rapidly captured swathes of southern Ukraine in the beginning of the invasion launched by Moscow exactly six months ago, but was repelled from around Kyiv and withdrew to focus on the east.

Moscow claimed the capture of the eastern region of Luhansk in early July after a series of long, bloody battles, but it has not claimed any major territorial gains since.

Separately, Budanov said that the Russian air defence systems in the annexed peninsula of Crimea “don’t really work”.

The comment, when asked about a spate of explosions on the peninsula for which Ukraine has not claimed responsibility, was one of the clearest hints yet that Ukraine may be conducting strikes there.

“Crimea … is defended by Russia’s best air defence systems,” he said. “They don’t really work, and they are not able to defend territory captured from Ukraine.”