Mexican President Andres Manuel Lopez Obrador on Thursday pledged to stick by his government's decision to give asylum to several people in Mexico's embassy in Bolivia, which has sparked a dispute with the interim administration in La Paz.
"It's a matter of principle," Lopez Obrador told reporters at a regular government news conference.
To hand over the people would mean abandoning what Mexico regards as a "sacred" right to grant asylum, he added.
Earlier this week, Bolivia expelled the Mexican ambassador to La Paz over the asylum spat, creating an awkward standoff for Lopez Obrador, who has sought to avoid foreign entanglements.
Mexico has not ejected Bolivia's ambassador in Mexico and Lopez Obrador said he would not react to provocations.
Relations have been rocky between the leftist Lopez Obrador and the conservative government in La Paz headed by caretaker president Jeanine Anez since Mexico gave asylum to Bolivia's former socialist leader Evo Morales in November.
Mexico gave refuge to nine people in La Paz, some of whom the Anez government, which is gearing up for presidential elections, has described as criminals and wants to put on trial.
The Mexican government has accused the Anez administration of harassing and intimidating its diplomatic staff in La Paz.
