Brazil President Michel Temer signed a decree Tuesday to send the army to "guarantee law and order" on the border with crisis-hit Venezuela after recent violent clashes.
Earlier this month, more than a thousand homeless Venezuelan immigrants who had flooded over the border into Brazil's northwestern Roraima state were driven back by an angry mob that rampaged through their makeshift tent following rumours a local shopkeeper had been brutally beaten by migrants.
Temer said his measure was aimed at providing "security for Brazilian citizens but also Venezuelan immigrants fleeing their country."
He also branded Venezuela's crisis as "tragic," saying it "threatens the harmony of practically the entire continent."
Temer called on "the international community to adopt diplomatic measures" to halt the Venezuelan exodus, as economic and political crises under President Nicolas Maduro's regime drive hundreds of thousands to leave in hope of finding a better life elsewhere.
The United Nations says some 2.3 million Venezuelans are living outside their homeland, with 1.6 million of those having left since 2015.
Oil-rich but over-reliant, Venezuela is in a fourth year of recession brought on by a crash in oil prices in 2014. Some 96 percent of the country's revenue is generated through crude.
Temer didn't reveal how many soldiers would be deployed to Roraima, but Defense Minister Joaquim Silva e Luna said "troops are already in place" on the border.
Security Minister Sergio Etchegoyen warned that Brazil "needs to discipline" the influx of migrants.