MEXICO CITY — After years of bowing to U.S. pressure to help slow migration, Mexico is drawing the line at a Texas law that would give the state a dramatically bigger role in border enforcement, including the right to deport undocumented migrants.

President Andrés Manuel López Obrador has denounced the measure as “draconian.” He says his government will reject any attempt by Texas officials to send migrants back to Mexico.

In an interview with The Washington Post, Foreign Minister Alicia Bárcena said the government would put “increased vigilance and controls” at border crossings to prevent such removals if the law goes into effect. That raises the specter of standoffs between Mexican and Texas state or local agents over attempted deportations.