Colombian President Gustavo Petro has proposed creating a military alliance to defend the Amazon.

He said the coalition would be like an "Amazonian NATO", a reference to the North Atlantic Treaty Organisation.

Mr Petro presented his idea during the Belem Summit in Brazil.

At the meeting, eight South American nations signed an agreement to protect the Amazon.

According to the Colombian president, the environment must not only be defended with ideas, but also "with weapons".

The summit was attended by leaders and representatives from Brazil, Colombia, Ecuador, Peru, Bolivia, Guyana, Suriname and Venezuela.