The U.N. General Assembly could vote as early as Thursday on a measure that would move the Palestinians from an observer state to a non-member observer state.
Palestinian leaders during last year's U.N. General Assembly meeting made a unilateral push for full membership at the United Nations as part of an effort to achieve statehood.
Victoria Nuland, a spokeswoman for the U.S. State Department, said told Washington's stance on the issue was clear.
"We've obviously been very clear that we do not think that this step is going to bring the Palestinian people any closer to a state" she said. "We think it is a mistake ... we oppose it."
A cease-fire between Israel and Hamas, brokered last week with the help of the Egyptian government, is holding.
Israeli newspaper Haaretz reports Tuesday that U.S.-Israeli efforts to persuade the Palestinians to abandon a clause in the resolution on criminal charges against Israeli officials failed.
Last year, members of the U.N. Education, Scientific and Cultural Organization received 107 votes in favor for membership for the Palestinian territories.