MEXICO CITY (Reuters) -Mexican President Andres Manuel Lopez Obrador on Tuesday said his government was preparing to challenge a new Texas law allowing state law enforcement to arrest suspected migrants, which he called "inhumane." On Monday, Texas Governor Greg Abbott signed the law giving local officers powers long delegated to the U.S. government. Migrants who enter the United States illegally can already be charged with illegal entry or re-entry under federal laws, but the governor of the border state has criticized what he calls U.S. President Joe Biden's failure to enforce them.