Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru and Suriname signed a pact, setting up a disaster response network and satellite monitoring, the BBC reported on Friday.
At a summit in Colombia, they also agreed to work on reforestation.
More than 80,000 fires have broken out in the Amazon rainforest this year.
"This meeting will live on as a co-ordination mechanism for the presidents that share this treasure - the Amazon," said Colombian President Ivan Duque, who hosted the summit in the city of Leticia.
Meanwhile, Peruvian President Martín Vizcarra said: "Goodwill alone is not enough anymore."
The seven nations also agreed to put more efforts into education and increase the role of indigenous communities.
The countries were represented in Leticia by presidents, vice-presidents and ministers.
Brazil's far-right President Jair Bolsonaro took part by videolink because he was preparing for surgery.
The Amazon is a vital carbon store that slows down the pace of global warming, and 60 per cent of it is located in Brazil.
The number of fires between January and August 2019 is double that of the same period last year, according to the country's National Institute for Space Research (Inpe).
President Bolsonaro has drawn intense domestic and international criticism for failing to protect the region.
Environmentalists say his policies have led to an increase in fires this year and that he has encouraged cattle farmers to clear vast swathes of the rainforest since his election last October.
Bolivia has also seen fires rage across the forest near its borders with Brazil and Paraguay.
Meanwhile, Brazil's leading meat export industry group and agricultural businesses have joined an environmental campaign calling for an end to deforestation in public lands in the Amazon and demanding government action.
Several international retailers have said they are suspending purchases of Brazilian leather because of the links between cattle ranching and the fires devastating parts of the Amazon rainforest.
( With inputs from IANS )