MEXICO CITY: Mexican President Andres Manuel Lopez Obrador has said that his government plans to challenge a law recently approved by the US state of Texas that allows authorities to arrest migrants suspected of illegally crossing the border.

"We are always going to be against these measures," Lopez Obrador said on Tuesday at a press conference, noting that the Foreign Affairs Ministry was in the process of legally challenging the law.

According to the President, Texas Governor Greg Abbott aims to rouse support with his anti-immigrant stance as he pursues the vice- presidential nomination of the Republican Party, Xinhua news agency reported.

Lopez Obrador described the Governor as "inhumane" and "cruel" for enacting the new law, known as Senate Bill 4, which criminalises illegal entry or re-entry into the state by classifying it as a state crime, with penalties ranging from 180 days to 20 years in prison.

The Mexican government estimates that more than 40 million Mexicans reside in the US.