A senior Mexican official told a United Nations human rights forum on Thursday that his government would defend the rights of Mexican migrants from discriminatory security measures.
Miguel Ruiz Cabanas, undersecretary for human rights, did not name the United States but he was clearly referring to the row with U.S. President Donald Trump over his proposed wall and U.S. hardline immigration policies.
Ruiz Cabanas also condemned what he called "populist ultra-nationalism".
Security measures targeting one part of the population or criminalizing certain groups violated the rule of law and were severely discriminatory, Ruiz Cabanas said in a speech to the U.N. Human Rights Council.
"This is why the government of Mexico reiterates its commitment to the defense of our nationals abroad," he said. "We want to make sure that all Mexicans are aware of their rights, and know how to react when faced with possible violations."
Mexicans are angry at Trump's calls for U.S. firms not to invest south of the border, his insults to immigrants, and threats to make Mexico finance the border wall.
"We also reiterate Mexico's conviction that walls between nations are also walls between people and bring about extremism and intolerance by having physical and ideological barriers that we will in no circumstances accept," Ruiz Cabanas said.
There was no immediate reaction from the U.S. delegation.
Ruiz Cabanas said that Mexico had just signed an agreement with the U.N. human rights office, testifying to "our cooperation and our openness to international human rights mechanisms".
Mexico has experienced a dark decade of drug violence, a menacing mix of murder, cover-ups and ineptitude.
U.N. High Commissioner for Human Rights Zeid Ra'ad al-Hussein, in a statement last week on the accord's signing, said his office would support efforts at tackling impunity and ensuring accountability in Mexico.
This included work on disappearances and torture, the rights of indigenous people, protecting activists and journalists, and access to justice, Zeid said.