Mexico will not accept deportations made by Texas “under any circumstances,” the country’s foreign ministry said on Tuesday in response to the U.S. Supreme Court’s decision to allow Texas to arrest migrants who cross into the state without authorization.

The ministry condemned the state law, known as Senate Bill 4, saying it would separate families, violate the human rights of migrants and generate “hostile environments” for the more than 10 million people of Mexican origin living in Texas.

Mexico’s top diplomat for North America, Roberto Velasco Álvarez, rejected the ruling on the social media on Tuesday, saying that immigration policy was something to be negotiated between federal governments.

The Mexican government has severely criticized the measure since last year, and rejected the idea of local or state agencies, rather than federal authorities, detaining and returning migrants and asylum seekers to Mexican territory.

“Texas has taken a very combative stance,” said Rafael Fernández de Castro, director of the Center for U.S.-Mexican studies at the University of California, San Diego. “It’s only aggravating the problem because you violently close one part of the border, but others are still open.”

A senior Mexican foreign ministry official who was not allowed to speak publicly said that the Supreme Court ruling would not affect existing migration agreements between the two countries.

While Mexico has served as the United States’ immigration enforcer, often discouraging migrants from massing at the border, the country has also publicly pushed for two key policies to address the root causes that force people out of their home countries — such as poverty, violence, inequality and climate change — and expand regular pathways for migration.

Last week, President Andrés Manuel López Obrador of Mexico said his administration was proposing that the Biden administration give legal status to at least five million undocumented Mexicans living and working in the United States.

He has also called on the United States to suspend sanctions against Venezuela and lift the blockade against Cuba, saying that such measures would reduce migration flows from those countries. And he has called proposals to build walls or close the border as “electoral propaganda.”

“Do you think the Americans and Mexicans will approve of this?” Mr. López Obrador said last month. “Companies cannot stand it. Maybe for a day, but not for a week.”