Brazil's defence ministry says it has intensified operations along the country's northern border amid a mounting territorial dispute between neighbours Venezuela and Guyana.
Venezuela is preparing to hold a referendum Sunday on whether it is the rightful owner of the oil-rich Essequibo region, which makes up more than two-thirds of Guyana.
Brazil says it has been following the situation.
The International Court of Justice today ordered Venezuela to refrain from any action that would "modify the situation that currently prevails in the territory in dispute".
Guyana had asked the ICJ to halt the referendum, saying it poses an "existential" threat to the country.
Guyana has administered Essequibo for more than a century.
But the territory is the subject of a decades-old dispute with Venezuela.