Much of the demand for ivory, as well as rhinoceros horn, is in Asia, and particularly China, where these items are used in traditional medicines and handicraft products, the report said.
The United States is widely considered to be the second-largest destination for illegally trafficked wildlife in the world, it said, with the European Union third.
Authorities in the United States have spoken out against the illegal trade in recent weeks.
Secretary of the Interior Sally Jewell announced this month that nearly six tons of elephant ivory seized by U.S. wildlife inspectors would be destroyed to highlight the issue.
"Rising demand for ivory is fueling a renewed and horrific slaughter of elephants in Africa, threatening remaining populations across the continent," Jewell said.
"We will continue to work aggressively with the departments of Justice and State, as well as with international law enforcement agencies, to disrupt and prosecute criminals who traffic in ivory, and we encourage other nations to join us in that effort."
The ivory stockpile, which includes whole tusks as well as smaller carvings and jewelry, has been kept at a secure site in Colorado, where it will be crushed and destroyed next month. Commercial ivory trade has been banned in the United States since 1989.
The Clinton Foundation is also working with conservation groups to try to halt the gruesome trade in tusks, by combating poaching and trafficking, and by educating consumers so they no longer buy ivory.
Chelsea Clinton wrote last month that elephant poaching had reached alarmingly high levels -- and was an issue with implications for global society.
"This is not just an ecological disaster; it is an economic and security threat as well," she said. "Tourism, a vital source of income for many of the most-affected African countries, is threatened if wildlife preserves are depopulated.
"The overall black market for illegal wildlife trade has become the fourth most lucrative criminal activity internationally, after drugs, counterfeit goods and human trafficking."