The federal agency charged with enforcing wildlife protection laws in the U.S. said Wednesday that it will investigate the highly publicized death of Cecil the lion in Zimbabwe, following accusations that an American citizen killed the animal illegally.

“The Service is deeply concerned about the recent killing of Cecil the lion,”a U.S. Fish and Wildlife Service spokesperson said in a statement. “We are currently gathering facts about the issue and will assist Zimbabwe officials in whatever manner requested.”

The statement follows an allegation by the government of Zimbabwe that Walter James Palmer, a 55-year-old Minnesota dentist, participated in the illegal killing of the lion earlier this month. Two Zimbabwe natives have also been implicated and appeared in court on Wednesday.

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The U.S. and Zimbabwe have an extradition treaty, but it remains unclear how the U.S. would respond to a request to extradite Palmer. In a statement, a spokesperson for the Department of Justice (DOJ) said that DOJ was “aware of the situation.” The spokesperson declined to say whether the U.S. had received an extradition request.

Palmer, who could not be reached for comment Wednesday, previously said that “everything about this trip was legal and properly handled and conducted” and promised to assist any investigations by government officials.

African lions face threats as a result of habitat loss and increased conflicts with humans, among other things. U.S. Fish and Wildlife Service proposed listing lions as an endangered species last year, which would create restrictions on lion hunting by U.S. citizens. The measure has yet to be decided.

“It is up to all of us—not just the people of Africa—to ensure that healthy, wild populations of animals continue to roam the savanna for generations to come,” a spokesperson for the agency said in a statement.

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Write to Justin Worland at justin.worland@time.com.