Mexico on Thursday greeted the decision by a US court to block a key provision of a controversial immigration law that would have required police to check suspects' immigration status, dpa reported.
The Mexican Foreign Ministry called the decision by a US judge on Wednesday as a "step in the right direction," according to media reports.
Foreign Minister Patricia Espinosa has instructed Mexico's four consulates in Arizona to document cases of violence and abuse against undocumented immigrants from Mexico.
Mexicans make up the largest proportion of illegal immigrants in the United States. An estimated half a million people illegally cross the 3,000-km border into the US every year in search of work.
The administration of US President Barack Obama had challenged the law in court. US District Judge Susan Bolton on Wednesday agreed with the Obama administration that the law would pre-empt federal authority to set US immigration policy.
She issued an injunction blocking the portion of the law that requires police officers to determine the immigration status of a person detained or arrested, saying it was "neither equitable or in the public interest."
Arizona Governor Jan Brewer, who had championed the law, said the state's attorneys would appeal the ruling "all the way to the Supreme Court, if necessary, for the right to protect the citizens of Arizona."
The ruling came just a day before it was due to go into effect.