Army trucks will serve as polling stations in Tuesday's election as authorities in states stricken by superstorm Sandy race against time to prepare for the vote.
Amid predictions that election tallies could be delayed because of the devastation, authorities in New York and New Jersey are still unsure how many polling stations will be ready.
Sandy "has the potential to create some chaos," said Costas Panagopoulos, an assistant professor at Fordham University in New York.
Department of Defence trucks are set to be used in New Jersey, which was worst hit by Monday's storm. About 3,000 of the sites hosting presidential, congressional and local elections have no electricity.
New Jersey's secretary of state, Kim Guadagno, said voters would find "a truck with a well-situated National Guardsman and a big sign saying: 'Vote Here.'" Paper ballots will be used where there is no electricity.
New Jersey and New York have also extended the deadline for postal ballots. In New Jersey, they will still be accepted on election day. In New York, absentee ballots can be received and counted up to November 19. Connecticut has also extended voter registration.
New York Board of Elections spokesman John Conklin said polling sites could be changed because of the storm.
Local boards in storm-stricken zones are assessing whether polling sites are fit for use.
"They are looking at whether the poll site has power, whether it could have power by election day, whether it's accessible to the general public. Can voters get to it?" Conklin explained.
New York may set up "super-polling" centres, grouping areas where voting has not been possible, officials said. In some areas - like New York's Queens borough, where fire destroyed many buildings - a tent could be used.
The storm has raised many questions about the election and when the final official result will be announced.
New York and New Jersey are both considered Obama strongholds, but the final result cannot be declared until all results are in.
New York Mayor Michael Bloomberg insisted the election would go ahead no matter what, while stressing it is not organised by the city.
"It's a shame if some bureaucrats were to screw it up and hopefully that won't happen. Voting is not just a right, it's a symbol of everything we fight and die for," he said.