For the first time, parents with children must wait in border cities while their asylum claims are processed.
The Nobel laureate, who faces a criminal complaint, denied one of the allegations and declined to comment on the second.
The plan has already raised numerous human rights concerns.
The government’s new measures will be implemented Friday at the San Ysidro port of entry south of San Diego and then expanded, officials said.
The blast north of Mexico City came amid a crackdown against oil theft.
The last group is widely seen as a success, even though thousands of its members are still stuck in Tijuana.
Since taking office, Andrés Manuel López Obrador has taken a cautious approach to his counterpart, in an apparently calculated move.
There are mile-long lines at filling stations. In some states, public transportation has been halted.
U.S. officials have thrown into question the citizenship of hundreds of Hispanic-Americans along the U.S.-Mexico border. The State Department said “border” area passport denials are the lowest in years.
U.S. agricultural exports to Mexico have increased dramatically under NAFTA.