The Bush administration plans to wait until after a Hamas-led government is in place to make final decision US aid programmes.
A delay of several weeks could give the administration time to iron out differences with its partners in the Quartet of Middle East mediators - the European Union, Russia and the United Nations - over how to sideline the Islamic militant group without collapsing the Palestinian economy.
The delay would also give the Bush administration time to see what policies Hamas puts in place and to assess how its government will be structured before announcing any decision.
The EU has likewise held back from deciding on its financial aid to the Palestinians, giving Hamas more time to act on calls to moderate its stance on Israel.
Hamas's government is expected to win parliamentary approval next week, but US officials said the administration's review of all aid programmes would not be completed for several more weeks, if not longer.
"The formal formation of a Hamas government is not the red line for our decisions on which aid programmes are going to go forward," said US Embassy spokesman Stewart Tuttle.
UN officials say they are concerned that a cut-off in assistance to a Hamas-led Palestinian Authority could trigger a humanitarian crisis and hobble the very institutions that would be needed to form any future Palestinian state.
In a recent report to donors, the World Bank said a sharp cut in funding from donors could push the West Bank and Gaza into a deep economic depression.
Israel has already frozen tax revenue transfers in a bid to isolate Hamas. As many as one in four Palestinians is dependent on wages from the Palestinian Authority, prompting warnings from international Middle East envoy James Wolfensohn that violence could break out if salaries are not paid.