A major concern for the Americans is that the Palestinians might use their new status to try to join the International Criminal Court. That prospect particularly worries the Israelis, who fear that the Palestinians might press for an investigation of their practices in the occupied territories.

Another worry is that the Palestinians might use the vote to seek membership in specialized agencies of the United Nations, a move that could have consequences for the financing of the international organizations as well as the Palestinian Authority itself. Congress cut off financing to the United Nations Educational, Scientific and Cultural Organization in 2011 after it accepted Palestine as a member. The United States is a major contributor to many of these agencies and plays an active role on their governing boards.

“To my knowledge, there’s no legislative impact that is triggered in the same way that there was with regard to Unesco,” Ms. Nuland said on Monday. “However, as you know, we also have money pending in the Congress for the Palestinian Authority, money that they need to support their regular endeavors and to support administration of the territories. So, obviously, if they take this step, it’s going to complicate the way the Congress looks at the Palestinians.”

Anticipating approval of the resolution, Western diplomats have pushed for a Palestinian commitment not to seek membership in the International Criminal Court and United Nations specialized agencies after the vote. Another step would be an affirmation by the Palestinians that the road to statehood was through the peace process. And a third could be a Palestinian commitment to open negotiations with the Israelis.

Such assurances do not appear to have been provided.

Israeli officials, aware that a harsh reaction would only isolate their country further, have begun playing down the significance of the draft resolution, and have toned down threats of countermeasures if it is approved. Israel’s response will be “proportionate” to how the Palestinians act after the vote, said an Israeli government spokesman, Mark Regev.