"Our slowed down counteroffensive is happening due to certain difficulties in the battlefield," Zelensky said in a interview with US media that aired on Wednesday.
Moreover, Zelensky said Ukraine has a shortage in artillery units that makes it difficult for its armed forces to be capable of hitting all its intended targets.
The Ukrainian official further emphasized that Ukraine wants the United States to provide the ATACMS long-range missile weapon system, and urged NATO to make some kind of announcement about Ukraine becoming a member of the alliance.
Earlier in the day, US media reported that the United States may announce this week whether to provide Ukraine with cluster munitions to aid in its counteroffensive.
Ukraine launched its much-touted counteroffensive in early June after multiple postponements. The Russian Defense Ministry has repeatedly said that Ukrainian troops are trying to advance in the South Donetsk, Artemovsk, and Zaporozhye directions, but without success.