It takes 3:1 manpower to perform land war offensives. They literally do not have the manpower.

They do have enough to hold their existing positions but they would literally just grind their human resources into dust by mounting anything other than a fake right now.

Noise about this is likely propaganda and also attempt at diversion as they're losing miles of ground in the east every day. Getting some Russian resources shifted around could give them time to entrench new eastern positions.

Edit: Missed a word.