The U.S. Fish and Wildlife Service on Thursday confirmed that it will try, once again, to develop a proposal to remove wolves from the Endangered Species Act protections across the Great Lakes region and in other parts of the Lower 48 states.

The agency has tried multiple times - through the Clinton, Bush and Obama administrations - to delist wolves in Minnesota, Wisconsin and Michigan, saying the big predators have fully recovered here after brushing with extinction in the 1960s and '70s.

The most recent of those efforts, in 2012, allowed state agencies to hold wolf trapping and hunting seasons for three years until late 2014 when a federal judge ruled that the agency had erred in taking wolves off the endangered list too soon.

That December 2014 decision was upheld in 2017 by a federal appeals court decision, keeping wolves protected across the region.

But the Trump administration said Thursday it will take its turn in developing a broader wolf proposal, for all areas of the Lower 48 states where wolves roam and are still protected, that will hold up in court.

An email statement from Gavin Shire, the U.S. Fish and Wildlife Service's chief of public affairs, said the agency "has begun reviewing the status of the gray wolf under the Endangered Species Act,'' the statement noted. "Working closely with our federal, state, tribal and local partners, we will assess the currently listed gray wolf entities in the Lower 48 states using the best available scientific information. If appropriate, the Service will publish a proposal to revise the wolf's status in the Federal Register by the end of the calendar year."

Similar efforts in the past have taken years to develop.

The renewed agency plan comes as efforts to pass legislation delisting wolves has stalled in Congress. Recent efforts to include wolf delisting in spending bills have failed and standalone wolf bills also have stalled without final action.

Livestock and some hunting groups support ending federal protections for wolves saying the animals have become too numerous.

Wolf supporters say that while the animals are thriving in the Great Lakes, that state agencies moved too fast to kill too many wolves once federal protections were withdrawn. Critics also note that wolves have not recovered across a broad portion of their original range, as the federal Endangered Species Act appears to call for.

"It's deeply troubling to see the Trump administration trying to prematurely kick wolves off the endangered species list," said Collette Adkins, a Minnesota-based attorney for the Center for Biological Diversity. "Time and again the courts have told the Service that wolves need further recovery before their protections can be removed. But the agency is dead-set on appeasing special interests who want to kill these amazing animals."

The Minnesota Department of Natural Resources estimated last year that the state has about 2,856 wolves. The Wisconsin DNR earlier this month said its annual winter survey showed as many as 944 wolves in the state, down about 2 percent from the estimated 956 last year, the state's modern-day record. Michigan's Upper Peninsula has more than 500 wolves.