Hunting advocacy group Safari Club International says it is "shocked" by the US Fish and Wildlife Service's temporary ban on importing elephant trophies from Zimbabwe and Tanzania and is calling for it to be rescinded.

Last week the USFWS announced it would suspend imports of all sport-hunted elephant trophies taken from the two African nations for the remainder of the 2014 calender year, citing poor regulations in Tanzania and Zimbabwe and a growing need to address the impact of illegal poaching on the countries' elephant populations.

Safari Club International said the decision to ban importing elephant trophies "relied solely on anecdotal evidence to make a rash decision with no basis in law, science, or conservation policy."

The USFWS cited "questionable management practices, a lack of effective law enforcement and weak governance" as leading to a rise in poaching. The authority advised hunters who've already booked elephant-hunting trips in Zimbabwe or Tanzania in 2014 that they will not be able to import any trophies and encouraged them to cancel their trips.

Safari Club International, however, contends that an absence of US game hunters in Zimbabwe and Tanzania will only increase instances of poaching.

"If anything, removing the US hunter from the landscape of Africa's great outdoors will permanently handicap government bodies and communal wildlife administrators in their fight against poachers," Safari Club International president Craig Kauffman wrote in an open letter to USFWS director Dan Ashe. "Problems with poaching in either Zimbabwe or Tanzania will be exacerbated by this ill-advised ban by the FWS."

Kauffman criticized the USFWS decision as a unilateral one that did not consider the position of the African government, which gain revenue from selling hunting permits. Kauffman said sport hunting revenue in Zimbabwe accounted for between 60-90 percent of all Zimbabwe's national parks department revenue.

The USFWS ruling would not prevent any American from participating in an elephant hunt in either of the countries.

"While you can still participate in a hunt in 2014, you would not be able to import the trophy, the USFWS said. "In addition, given the conservation concerns for elephants in Tanzania and Zimbabwe, we strongly advise that you reconsider taking part in an elephant hunt in either of these countries."