The U.S. Fish and Wildlife Service on Tuesday announced a proposal to classify both wild and captive chimpanzees as endangered, a move that could affect future use of chimpanzees in scientific research in the United States.

The agency said the rule proposed would "correct the inconsistency" that only wild chimpanzees are listed as endangered while captive chimpanzees are listed as threatened in the country.

If this proposal is finalized, certain activities would require a permit, including import and export of chimpanzees into and out of the United States, said the agency.

Permits would be issued only for scientific purposes or to enhance the propagation or survival of the affected species, including habitat restoration and research on chimpanzees in the wild that contributes to improved management and recovery, it said.

The proposal comes months after a decision by the U.S. National Institutes of Health to "retire" many of the over 400 chimps that it supports at primate facilities.

Chimpanzees are found in a wide but discontinuous distribution in 22 countries of Equatorial Africa. Widespread poaching, capture for the pet trade, and outbreaks of disease are impeding chimpanzees' ability to sustain viable populations in the wild, the agency said. Endi