This has been the stance of the US for a looooong time. Why do you think they (along with Russia, China, and a few others) have never signed the treaty accepting the court's jurisdiction?
This isn't incredible. This is the status quo
The only reason the US (and Russia, and China) agree to work with the UN is because they have permanent unilateral veto power on any decision that may affect them or their interest. They only acknowledge international law because they control it.