Under the rule, people arriving via a third country must claim asylum there first before arriving at the United States border.
On Thursday, López Obrador said that he spoke by phone with President Donald Trump a day prior, noting the US president recognized Mexico's efforts and that relations between the two countries were very good.
(The ruling was issued without an explanation.) But it's disturbing, and disheartening, that the USA government and the nation's highest court so willingly disregard the health, safety and legal rights of people in desperate need.
The likelihood of a further tightening of the USA government's stranglehold on asylum seekers at the U.S. border comes as the number of Central Americans crossing into the country has already steadily declined in recent months. A three-judge panel of the 9th U.S. Circuit Court of Appeals narrowed Tigar's order so that it applied only in Arizona and California, states that are within the 9th Circuit.
"BIG United States Supreme Court WIN for the Border on Asylum!" he tweeted at 6:47 p.m. on September 11.
"In effect, the rule forbids nearly all Central Americans [.] to apply for asylum in the United States if they enter or seek to enter through the southern border, unless they were first denied asylum in Mexico or another third country", she wrote.
Mexico 'disagrees' with Trump asylum restrictions
Meanwhile, the administration has forced 42,000 asylum seekers who reached the U.S.to wait in Mexico while their applications are processed, and is opening two temporary sets of courtrooms in tent complexes in the border towns of Brownsville and Laredo, Texas, to handle the cases.
Asylum seekers must pass an initial screening called a "credible fear" interview, a hurdle that a vast majority clear. However, under the new rule, candidates can not pass unless they have sought asylum in at least one country they traveled through, and were denied.
Two of the nine Supreme Court justices - Sonia Sotomayor and Ruth Bader Ginsburg - disagreed, or dissented. It's unclear how quickly the policy will be rolled out and how exactly it fits in with the other efforts by the administration to restrict border crossings and tighten asylum rules.
Lee Gelernt, an attorney with the American Civil Liberties Union, one of the groups challenging the asylum restrictions, expressed hope that "we'll prevail at the end of the day". "The lives of thousands of families are at stake".
In December, a divided Supreme Court refused to let Trump start automatically rejecting all asylum claims by people who cross the southern border illegally. There are thought to be at least 45,000 Central Americans who have been turned away by U.S. agents and forced to wait within Mexico while their asylum claims are processed, which can take many months.
Opponents argue the policy violates worldwide law by forcing people fleeing for their lives to seek refuge in countries where they may also be in danger.