Argentina toughened its immigration law, making it easier to deport foreigners who commit crimes or who are being investigated.
The changes to the 2003 law were implemented by presidential decree, which cites a rise in organized crime committed by foreigners.
It restricts those serving sentences or with criminal records from entering Argentina and fast tracks the expulsion of foreigners who commit crimes including drug dealing, arms trafficking or money laundering.
The government yesterday said authorities faced bureaucratic hurdles in deporting foreigners who committed such crimes.
The toughening of the law is in stark contrast to Argentina's traditionally welcoming immigration policy. It seeks to curb a spike in crime that remains a top concern for Argentines ahead of this year's congressional elections.
Human rights advocates said it risks stigmatizing foreigners who make up 4.5 per cent of the 40 million people living in Argentina.
"Amnesty International considers that it's a mistake to reduce the migration phenomenon to a debate on national security that associates migrants with criminals," the rights organization said in a statement on Monday.
"Even when States have the authority to establish rules in migratory issues, they can't violate the rights guaranteed under the constitution and international human rights treaties," it added.
Amnesty said the overhaul of the immigration law is a regressive move, introducing roadblocks for the entrance and residence of migrants, speeding up expulsions, reducing procedural guarantees and breaching rights to a legitimate defense.
Argentine Vice President Gabriela Michetti defended the changes law and distanced the move from US President Donald Trump's action on refugees and migrants.
"You have to make a distinction between measures that have to do with security," she told a local radio station.
"Argentina is an open country that will always be in favor of diversity."
Trump banned travelers from seven Muslim-majority nations, suspended refugee admissions for 120 days and indefinitely barred the processing of refugees from Syria.
"Just like Trump's government, (Argentine President Mauricio) Macri is criminalizing immigration through executive orders that modify national laws and international commitments," said Argentine activist Adolfo Perez Esquivel, who won the Nobel Peace Prize in 1980 for his defense of human rights during Argentina's "dirty war."
"Avoiding lawmakers, they are committing a clear violation of human rights in the name of security, when security problems can and should be solved respecting our constitution and increasing our rights, not reducing them," he said.