"The application for stay presented to Justice Kagan and by her referred to the Court is granted, and the district court's April 8, 2019 order granting a preliminary injunction is stayed pending the timely filing and disposition of a petition for a writ of certiorari", the filing said.
The Supreme Court has overruled a decision by the US Court of Appeals for the Ninth Circuit in late February granting a temporary block of the MPP program, which requires migrants seeking asylum in the United States to stay in Mexico while they await their immigration proceedings.
The appeals court said the Trump administration's policies were inconsistent with US and international laws and temporarily blocked the MPP and a presidential proclamation that disqualified certain migrants' eligibility for asylum.
American Civil Liberties Union (ACLU) lawyer Judy Rabinovitz in a statement on Wednesday said the Supreme Court should also declare the MPP policy to be illegal, adding that it exposes migrants to "grave danger and irreversible harm".
About 56,000 asylum-seekers along the US southern border have been subjected to the Trump administration's MPP policy with very few migrants granted asylum.
Trump's MPP Policy
The Remain in Mexico policy, known as the Migrant Protection Protocols (MPP), requires asylum-seeking migrants to wait in Mexico while they wait for their court proceedings. MPP has reportedly been a crucial program in helping address the migration crisis on the US-Mexico border.
Caravans of migrants from Central American countries seeking asylum began to move toward the United States through Mexico in fall 2018. US President Donald Trump called the surge of arrivals a crisis and declared a national emergency in February to secure funds to build a wall on the border with Mexico.
Under the agreement, the United States will provide training and mentoring to law enforcement and immigration officials to improve the capacity of the three nations to combat migrant trafficking and human smuggling transiting through the region.
According to US Customs and Border Protection (CBP), apprehensions of illegal border crossers from the three Central American nations have recently slowed to about 10,000 per month in the final three months of 2019 compared with monthly rates exceeding 100,000 each month.