Theoretically, the U.S. could be forced to abstain from UN Security Council ceasefire resolutions for Gaza because regulations bar parties to the underlying conflict from voting. The U.S. is arguably a party to the conflict. From Mike Whitney at unz.com:

Are Washington’s Voting Rights on the UN Security Council at Risk? “…a party to a dispute shall abstain from voting.”
The main obstacle to a ceasefire in Gaza is not Israel or Hamas. It’s the United States. Here’s what you need to know: The Security Council approved the Biden-authored ceasefire deal on June 10, 2024. (Three months ago) US diplomats assured the other members of the Security Council that Israel supported the agreement. That claim turned out to be false. Israel does not back the deal and refuses to implement its provisions. Even so, the so-called Biden Plan passed the Council in the form of Resolution 2735. Here’s a summary of the agreement:
By resolution 2735 … the 15-member organ noted that the implementation of this proposal would enable the following outcomes to spread over three phases, the first of which would include an immediate, full and complete ceasefire with the release of hostages; the return of the remains of some hostages who have been killed; the exchange of Palestinian prisoners; withdrawal of Israeli forces from the populated areas in Gaza; the return of Palestinian civilians to their homes; and the safe and effective distribution of humanitarian assistance at scale throughout Gaza. Adopting Resolution 273 5, United Nations
There’s no ambiguity here, the Council’s demands are clear. Both parties to the conflict are required to implement the provisions of the resolution that are “binding” under international law.