A young man traveling with a migrant caravan looks through a border fence into the United States at Playas de Tijuana in Tijuana, Mexico, on November 28. Photo by Ariana Drehsler/UPI | License Photo

A migrant family looks at a border fence that divides the United States and Mexico Sunday near Las Playas de Tijuana, Mexico. Photo by Ariana Drehsler/UPI | License Photo

Migrants climb over a border fence in Tijuana, Mexico, Sunday that divides the United States and Mexico. Photo by Ariana Drehsler/UPI | License Photo

With growing frustration at the length of the asylum process, migrants climb over a border fence that divides the United States and Mexico Sunday near Las Playas de Tijuana, Mexico. Photo by Ariana Drehsler/UPI | License Photo

People stand on the beach on the Mexican side of the border fence, at left, in Tijuana, Mexico, on November 28. File Photo by Ariana Drehsler/UPI | License Photo

Dec. 3 (UPI) -- The U.S. Supreme Court rejected an appeal Monday that challenged construction of the Trump administration's planned border wall, on environmental grounds.

The justices left intact a prior court ruling that clears the way for the Trump administration to build two segments of replacement fence and several wall prototypes.


The Animal Legal Defense Fund, Defenders of Wildlife and Center for Biological Diversity argued the federal Illegal Immigration Reform and Immigrant Responsibility Act violates the constitutional separation of powers established by the Constitution.

The 1996 law gives the Homeland Security Department sweeping authority to waive all legal requirements slowing construction of a border wall, and restricts judicial review of such determinations.

The plaintiffs argued the department's authority was so vast that it violates the separation of powers. In denying the petition, the high court refused Monday to hear the groups' appeal.

The groups had argued habitats of rare plant and animal species would be harmed by the proximity of a wall.

Legal waivers allowed work to proceed on a 14-mile stretch of fencing, as high as 30 feet in some places, from the Pacific Ocean eastward to Calexico, Calif.

The original ruling left intact was issued by U.S. District Court Judge Gonzalo Curiel, who wrote that the waiver authority is a legitimate way to "avoid delays caused by lawsuits challenging the construction of barriers."

During the 2016 presidential campaign, then-candidate Donald Trump attacked Curiel, who was born and raised in Indiana, as a "Mexican" and a "hater" incapable of impartiality in presiding over a lawsuit against Trump University.

"We would save Billions of Dollars if the Democrats would give us the votes to build the Wall," Trump tweeted Monday. "Either way, people will NOT be allowed into our Country illegally! We will close the entire Southern Border if necessary. Also, STOP THE DRUGS!"