"We will not give any indication where, in our opinion, the main Ukrainian counteroffensive could take place," Mason Clark, an analyst at the Institute for the Study of War (ISW), warned on Thursday. ISW analysts are also read in Moscow.

The Pentagon also declined Friday to qualify the ongoing fighting. "We take the security of Ukrainian operations very seriously," said ISW analyst Mason Clark with gravity. "It's something... that is very, very serious," he added.