I mean, that's part of the given justification for the veto, but it doesn't take a PhD in international relations to figure out that the real reason is obviously that both the US and Israel --and a number of other relevant players-- are currently knee-deep in operations and negotiations and that a cease fire, by changing the dynamic on the ground, would seriously screw those efforts.

My guess is that Israel has a plan that it wants to execute before implementing any cease-fire, and that the US is on-board with it for now.

Unlike most social media users, I don't feel like I know enough to take a position on whether this veto is morally justifiable or not. On its face it seems kind of lame, but I can easily think of reasons why it might actually be entirely justified. We will see.