Ukrainian Prime Minister Denys Shmyhal was quoted in a Politico article published Monday as saying that Ukraine estimated that Russia only had about “four dozen” hypersonic missiles left.

“These are the ones that have precision and accuracy due to the microchips that they have,” he said. “But because of sanctions imposed on Russia, the deliveries of this high-tech microchip equipment…have stopped and they have no way of replenishing these stocks.”

Russia’s limited microchip and hypersonic missile supply, if true, could be another sign of trouble for Russian President Vladimir Putin’s regime in a war that has now stretched on for longer than six months.

Shmyhal, citing Ukrainian information, also told Politico that Russia has “already spent almost half…of their weaponry arsenal.” Newsweek was not able to independently verify the Ukrainian prime minister’s claims and reached out to Russia’s Defense Ministry for confirmation and comment.

Ukraine is issuing warnings that Russia has put together lists of semiconductors, transformers and other equipment, many of which are manufactured by companies in the U.S., U.K., and Germany, that it is trying to obtain in order to support its war push, Politico reported. The New York Times reported Monday, citing newly declassified intelligence, that sanctions imposed in response to the Ukrainian invasion had forced Moscow to resort to buying millions of artillery shells and rockets from North Korea.

Russia has also been purportedly ramping up recruitment efforts to make up for troop losses, while the retired four-star U.S. Army General Barry McCaffrey said Monday that Putin has his country stuck “in a box” against Ukraine.

Ukraine launched a counteroffensive in the Russian-occupied southern Kherson region last week and has already reported achieving several victories in the push. These include the recapture of the village of Vysokopillia on Sunday, a victory announced on Telegram by Yuriy Sobolevskyi, first deputy head of Kherson Oblast Council.

The Institute for the Study of War (ISW), a U.S. think tank, wrote in its September 5 campaign assessment that the Ukrainian counteroffensive is “tangibly degrading Russian logistics and administrative capabilities in occupied southern Ukraine.”

Speaking to ABC’s World News Tonight anchor David Muir, Ukrainian President Volodymyr Zelensky hinted that additional counteroffensives may be taking place, but declined to elaborate more.

“I won’t say that it’s only a counter-offensive in Kherson,” Zelensky said. “There is a direction or directions, plural, and we have to move forward.”

But Russia’s expressed certainty about its ability to succeed in the war has not wavered. Russian Foreign Ministry Spokeswoman Maria Zakharova said during an August 31 press briefing that “allied forces are advancing slowly but surely” and all of Russia’s goals in Ukraine “will definitely be attained.”