A prominent environmental group and a senior Democrat in the House joined forces Wednesday to file the first lawsuit against President Trump's plans to build a wall along the Mexican border.

The Center for Biological Diversity, a group heavily involved in protecting endangered species, and Rep. Raul Grijalva, D-Ariz., sued the Trump administration on the grounds that it violates laws protecting endangered species and public lands, arguing that the wall would "divide and destroy" communities and habitat along the border.

"Trump's wall — and his fanatical approach to our southern border — will do little more than perpetuate human suffering while irrevocably damaging our public lands and the wildlife that depend on them," Grijalva said Wednesday.

"Endangered species like jaguars and ocelots don't observe international boundaries and should not be sacrificed for unnecessary border militarization," said Kierán Suckling, the group's executive director.

Grijalva, the top Democrat on the House Natural Resources Committee and co-chairman of the Progressive Caucus, said the administration should seek to uphold U.S. environmental laws, which he described as "some of the oldest and strongest in the world," not ignore them.

He said a double standard shouldn't exist on how the laws are applied, be it on the border or anywhere else.

The conservation group said the lawsuit was the first leveled at the Trump administration since the president signed an executive order in January to build it.

Also on Wednesday, a group of Democrats in the Senate sent Trump a letter asking that he block a Republican effort on Capitol Hill to roll back national monument designations in the West. They used promises Trump made during the 2016 campaign to protect federal lands to persuade him to act and stand by his word.

"We urge you to honor your promise to be a great steward of our public lands by upholding the existing protections for the 157 national monuments that have been designated through the years by nearly every president since the Antiquities Act was enacted into law in 1906," read the letter, led by Sen. Tom Udall of New Mexico.