Brazilian President Michel Temer says the government is seeking funding from companies and banks to help rebuild the National Museum in Rio de Janeiro after it was destroyed by fire.
Education Minister Rossieli Soares said international help was also being sought and talks with the UN’s cultural body, Unesco, were under way.
Museum officials say almost 90% of the collection has been destroyed.
Staff have blamed the fire on years of funding cuts.
The museum housed one of the largest anthropology and natural history collections in the Americas. It included the 12,000-year-old remains of a woman known as “Luzia”.
On Monday, President Temer’s office said he had held talks with officials from major Brazilian banks and businesses to examine ways to reconstruct the museum “as soon as possible”.
Addressing reporters outside the ruined building, Mr. Soares said the federal government had set aside an initial 15m reais (£2.8m; $3.6m) to rebuild the structure and restore its collection.
An investigation has been launched but Culture Minister Sergio Leitao told the Estado de S.Paulo newspaper that the most likely causes were an electrical fault or a homemade paper hot-air balloon landing on the roof.
The fire started on Sunday evening, after the building – a 19th Century former royal palace – closed for the day.
It is not yet clear if the museum was insured.
The city’s fire chief, Roberto Robadey, said nearby hydrants were dry when emergency services arrived. He said crews had to get water from a nearby lake and from tanker trucks.
“Yesterday was one of the saddest days of my career,” he said.
On Monday, fire crews were sifting through the charred wreckage, occasionally emerging with an artefact or a painting they had managed to rescue.