At least 112 people have been killed by forest fires in Chile's Valparaíso region, local authorities have said.
Gabriel Boric declared a state of emergency and said he would make "all necessary resources" available to tackle the situation.
It is believed to be Chile's deadliest forest fire on record. Many of those affected were visiting the coastal region during the summer holidays.
A health alert was put in place in Valparaíso by the health ministry.
The ministry called for the suspension of elective surgeries and authorised temporary field hospitals to be set up.
Medicine students nearing the end of their studies will be hired to help ease pressures on the health service, the ministry announced in the same statement.
Rescue services have struggled to reach the most badly affected areas and Interior Minister Carolina Tohá said the death toll would "reach much higher figures" in the coming hours.
The Chilean government has urged people not to travel to the areas hit by the fires.
A 61-year-old resident from El Olivar described the ordeal as "hell".
Speaking to the AFP news agency, Rodrigo Pulgar said he tried to help his neighbour but then realised that his own house had started to burn.
"Ash was raining down on us," Mr Pulgar added.
He explained that most residents in El Olivar are older people, and said his neighbour died because they couldn't get her out.
The housing ministry said between 3,000 and 6,000 houses were impacted by the fires.
On Saturday, a curfew was put in place for those in Viña del Mar, Limache, Quilpué and Villa Alemana.
Mr Boric said the curfew will help free up routes and allow emergency vehicles to reach affected areas.
Some 1,400 firefighters are being deployed on Sunday, the interior minister said in an address to the nation.
Military personnel have been deployed alongside emergency services, and the cause of the fires is being investigated.
To avoid the escalation of an already delicate situation, the government has banned the handling of fire and machines that produce heat in Valparaíso, and the nearby Marga Marga region.
Situated 116 km (72 miles) from the capital Santiago, the coastal town of Valparaíso sees many tourists during the summer.
Last year, the regions of Biobío and Ñuble - further south from Valparaíso - endured deadly wildfires, which appear to be becoming more frequent and lethal.