Colombia and Brazil have tightened border controls with Venezuela as both nations grapple with a mounting influx of hundreds of thousands of desperate migrants fleeing a worsening economic crisis.
In a visit to the border region, Colombian President Juan Manuel Santos said he would impose stricter migratory controls, suspend new daily entry cards for Venezuelans and deploy 3000 new security personnel along the frontier.
Speaking in Colombian border city Cucuta, Santos warned his government would strictly prosecute any unlawful behaviour by Venezuelans amid concerns over rising crime.
He said Colombia was spending millions of dollars to support the migrants.
Brazil's defence minister, Raul Jungmann, speaking in the northern border town of Boa Vista, said the government would also deploy more troops and start relocating tens of thousands of Venezuelan refugees.
Both countries said they would take measures to count the number of Venezuelan migrants who have entered their territory: Brazil through a census and Colombia through a registry.
The moves to tighten border security could threaten a key social safety valve for desperate Venezuelans as hyperinflation and a severe recession grip their oil-rich country.
The steps also signalled a mounting regional frustration with Venezuela's unpopular President Nicolas Maduro, who will seek re-election on April 22 amid conditions the US and other countries say are stacked against a divided opposition.
Maduro is expected to win re-election despite a recession that is now in its fifth year.