The US Supreme Court on Wednesday effectively ruled the Biden administration would have to reinstate a controversial immigration policy that it has sought to suspend. 

The ruling upholds a Texas court ruling ordering the Biden administration to make a "good faith effort" to restart the "Remain in Mexico" policy. 

What is the immigration policy?

Implemented in 2019, the policy forced Mexican asylum-seekers to wait behind the Mexican border instead of being allowed to enter the US to seek asylum.

The policy, officially known as "Migrant Protection Protocols," broke from the previous US practice of allowing those fleeing violence from Mexico to enter the US and apply for asylum.

Former president Donald Trump implemented the policy in 2019. More than 60,000 asylum seekers have been sent back to Mexico since January 2019.

Joe Biden had campaigned on ending the immigration policy and suspended it on the first day of taking office this January. However, the president left a window for review before shutting it down completely. 

It is not clear how many people will be affected by Tuesday's Supreme Court ruling, or if the Biden administration will again try to end the program. 

How have immigration authorities reacted?

The Homeland Security Department reacted quickly to the Supreme Court ruling. It said in a statement that it regrets the Supreme Court decision to reinstate the immigration policy and that it "will continue to vigorously challenge it."

The Biden administration has previously argued that the Homeland Security Secretary Alejandro Mayorkas has discretion in deciding whether to return asylum seekers to Mexico, and the president has "clear authority" to determine immigration policy. 

The American Civil Liberties Union (ACLU) has called on the administration to present a fuller rationale for ending the program, which would be able to stand up to legal scrutiny.

"The government must take all steps available to fully end this illegal program, including by re-terminating it with a fuller explanation. What it must not do is use this decision as cover for abandoning its commitment to restore a fair asylum system," said Omar Jadwat, director of the ACLU's immigration rights project. 

What is the Supreme Court ruling based on?

Earlier this month, US District Judge Matthew Kacsmaryk ruled that the Biden administration had failed to provide a legally adequate rationale for getting rid of the policy.

He ordered that the policy would have to remain in place until the administration undergoes a lengthy administrative procedure to overturn it.

The Supreme Court's conservative majority agreed that the Biden administration had not done enough to overturn the policy.

US Democrats and immigration advocates have criticized MPP, saying it subjected Central American migrants to unsanitary conditions and violence.

Arrests of migrants caught crossing the US-Mexico border have reached 20-year highs in recent months, a trend Republicans pin on Biden's reversal of MPP.

rm/wmr (Reuters, AP)