(Reuters) - Environmentalists sued the Trump administration on Tuesday, claiming its recovery plan for the endangered Mexican wolf would instead lead to the extinction of one of North America’s most imperiled mammals.

Slideshow ( 2 images )

The U.S. Fish and Wildlife Service in November released a program it said would restore the Mexican wolf to sufficient numbers in Arizona, New Mexico and Mexico by 2043, allowing it to be removed from the endangered species list.

But WildEarth Guardians argued in one of two separate lawsuits filed by environmental groups in U.S. District Court in Arizona that the plan would further imperil the smallest and rarest subspecies of the gray wolf that roams parts of the U.S. West and Midwest. The second lawsuit was filed by Defenders of Wildlife and others.

“This is not a recovery plan, it’s an extinction plan for the Mexican wolf,” Chris Smith, wildlife advocate for WildEarth Guardians, said by telephone on Tuesday.

Conservationists in both lawsuits want the court to find the Fish and Wildlife Service plan legally flawed and require the agency to craft a new one.

A spokesman for the Fish and Wildlife Service did not immediately respond to a request for comment on Tuesday. The agency in the past has said it has a policy of not commenting on litigation.

The Mexican wolf had disappeared in the wild when it was first classified as endangered in 1976 and has struggled to make a comeback despite decades of conservation efforts.

Environmentalists assert in the lawsuits that the government’s recovery program cuts Mexican wolves off from their historic range in and around Grand Canyon National Park in Arizona and the Southern Rocky Mountains, leading to geographic isolation and inbreeding that would diminish the size and health of wolf packs.

Conservationists accused the Fish and Wildlife Service of bowing to pressures exerted by livestock and hunting groups – which see wolves as threats to cattle and big-game animals favored by sportsmen – instead of using science to determine population levels and other factors key to the Mexican wolf’s survival.

Under the agency’s plan, the Mexican wolf, which numbers 113 in Arizona and New Mexico and 31 in Mexico, would be eligible for de-listing in 2043 provided its population reached an average of at least 320 in the two U.S. states and 200 in Mexico over eight years, assuming a steady growth rate during that period.

Government wildlife managers have hailed the measures as opening “a path forward” for an animal that had all but vanished in the American Southwest in the 20th century due to systematic hunting, trapping and poisoning.