The US didn't propose a ceasefire yet. In response to this ceasefire proposal they've said they're working on a draft for a proposal. With an indeterminate ceasefire of indeterminate length to start at an indeterminate date.

But strangely, once actual dates and times get proposed, they bring out the veto.

One could argue that it sure looks like they're trying to muddy the waters and give Israel cover.

As far as I know, Biden imposed sanctions on 4 INDIVIDUAL MEN and went "Fine, I sanctioned Israel, are you all happy yet?"

US will always support Israel's actions, regardless of what it appears to say or do in public.