Two million people have been affected by the massive earthquake that struck central Chile on Saturday, President Michelle Bachelet has said.
In a TV address, she said the forces of nature were testing the nation.
So far at least 300 people have been confirmed killed in the earthquake that struck in the early hours of Saturday.
The 8.8 quake - one of the biggest ever - triggered a tsunami that has been sweeping across the Pacific, although waves were not as high as predicted.
"The forces of nature have badly affected our country," Ms Bachelet said.
"And once again they've put to the test our ability to deal with adversity and get back on our feet. And we are examining every way to restore all the basic services in the country. But there's still a lot to do.
Ms Bachelet added that she had declared a state of catastrophe in six regions.
Chile is vulnerable to earthquakes, being situated on the Pacific "Ring of Fire" where the Pacific and South American plates meet.
The earthquake struck at 0634 GMT, 115km (70 miles) north-east of the city of Concepcion and 325km south-west of the capital Santiago at a depth of about 35km. It is the biggest to hit Chile in 50 years.
Widespread damage to roads and buildings has been reported in many areas, including the capital where a chemical plant caught fire.
Electricity, water and phone lines have been cut.
At least 85 people died in the region of Maule alone, journalists there reported.
Many deaths were also reported in the regions of Santiago, O'Higgins, Biobio, Araucania and Valparaiso.
TV pictures showed a major bridge at Concepcion had collapsed into the Biobio river.
Rescue teams are struggling to reach Concepcion because of damage to infrastructure, national media reported.
In Santiago, where at least 13 people were killed, several buildings collapsed - including a car park.
A fire at a chemical plant in the outskirts of the capital forced the evacuation of the neighbourhood.
Santiago international airport's terminal was damaged and will be closed for at least 72 hours, officials said. Flights are being diverted to Mendoza in Argentina.
A tsunami triggered by the earthquake struck the Juan Fernandez island group off the Chilean coast and local media say five people died there with several others missing.
As the tsunami radiated across the Pacific, Japan warned that a wave of 3m (10ft) or higher could hit the Pacific coast of its northernmost island of Hokkaido at about 1300 local time (0400 GMT).
In French Polynesia, waves 6ft (1.8m) high swept ashore, but there were no immediate reports of damage.
Hawaii later lifted its tsunami warning after waves measuring just under 1m (3ft) high struck but caused no damage.