The Pacific area, including Hawaii, has been warned of potentially powerful tsunamis while the US and Canadian west coasts and Alaska have been put on alert.
The move comes after a 8.8 magnitude earthquake in Chile earlier today generated large waves which are travelling towards the Hawaiian Islands, the National Weather Service's Pacific Tsunami Warning Center said in a statement.
"Urgent action should be taken to protect lives and property," the service said of the Hawaii threat. Residents have been awakened by the city's 176 sirens, said John Cummings, spokesman for the Department of Emergency Management in Honolulu.
"Residents are awake and fully aware of what's happening," Mr Cummings said.
"Right now we are primarily concerned with residents who live on the coast and in the evacuation zone. They should leave the shoreline, pack some things in the car and drive inland. If you're not in the zone, stay inland," Mr Cummings said.
The US and Canadian west coasts are under an advisory, which means that while significant, widespread inundation is not expected, currents may be hazardous for swimmers, boats and nearby structures.
The Federal Emergency Management Agency and the Department of Homeland Security "are closely monitoring the situation, and officials are in close contact with the State of Hawaii and the US territories in the Pacific Ocean that could be impacted by a potential tsunami," FEMA Administrator Craig Fugate said in a statement.
An evacuation of Easter Island was ordered, Chilean President Michelle Bachelet said. Residents on the Pacific Ocean island, 3,510km west of the South American mainland, were later told by the Chilean navy that the threat of a tsunami had eased.
A weak tsunami struck French Polynesia in the south Pacific without causing "notable" damage, Agence France-Presse reported.
PA/Reuters/Bloomberg