Mahmoud Abbas' statement Wednesday signaled a hardening of his position. Previously, he had said he would turn to the U.N. only if peace talks remain deadlocked.
Negotiations have been stalled for nearly three years, and U.S. diplomats have been trying to revive the talks.
Abbas' comments to Palestinian officials in the West Bank city of Ramallah indicate he is preparing for a confrontation with Israel and the U.S.
The two countries oppose the U.N. move, saying disputes should be resolved through negotiations. The Palestinians acknowledge a U.N. vote would be largely symbolic, but believe it would send a message to Israel.