U.S. President Donald Trump says he is putting on hold a decision to allow imports of big game trophies until he can “review all conservation facts.”

Trump tweeted Friday that he will review the issue with Interior Secretary Ryan Zinke. He said the policy has been “under study for years.”

The abrupt change in policy follows an announcement Thursday by the U.S. Fish and Wildlife Service, which said it will allow the importation of body parts from elephants shot for sport in Zimbabwe and Zambia.

The agency concluded that encouraging wealthy big-game hunters to kill the threatened species would help raise money for conservation programs.

Both animal rights groups and environmental groups criticized the decision, saying it could deplete at-risk elephant populations.

The top Republican on the House Foreign Affairs Committee, Ed Royce, was also critical of the move Friday, because of concerns about African wildlife and also the current political upheaval in Zimbabwe.

“The administration should withdraw this decision until Zimbabwe stabilizes,’’ he said in a statement.

The Great Elephant Census reported last year that Zambia had just more than 21,000 elephants last year, while 82,000 elephants roam in Zimbabwe. Overall elephant populations have declined by 30 percent in 18 African countries between 2007 and 2014, with slightly more than 350,000 still alive in the wild.

African elephants have been listed as threatened under the U.S. Endangered Species Act.