The US is not signatory to the ICC, so therefore has no say in its decisions. Sorry, you don't get to boss around a group you're not a part of.
The problem is that the ICC declares universal jurisdiction and only requires a party to it to bring a case for it to target someone outside of it. So they are essentially saying that we are all part of it whether we want to be or not.
It would be really problematic if states committing war crimes could simply declare themselves not subject to ICC jurisdiction.
Except that's already what happens. The ICC can't do anything about the Chinese treatment of the Uyghurs, can't do anything about the Saudis massacring migrants and murdering dissidents, can't do anything about American soldiers murdering innocent people in the Middle East (Ed Gallagher.) In practice, the only people ever prosecuted at the ICC have lost power in their home countries and been handed over voluntarily. But Bibi is still nervous about this. Why? He's hanging onto power by a flimsy thread, and he knows it.
