Professor Sumiya Jambaldorj from the Genghis Khan University in the Mongolian capital, UIan Bator, performed a study proving the similarity between American place names and words in the Mongolian language.
"About 8,000 to 25,000 years ago, Mongols with stone tools crossed the Aleutian Islands and arrived in America," Jambaldorj was reported as saying.
The academic said that over 20 place names in the Alaskan Aleutian Islands could be Mongolian.
"Many names of places and rivers in the U.S. state of Alaska are believed to be Mongolian," he said.
The news agency said there were similar words in a Native American language and Mongolian, e.g. "hagaan," which means "ancestor" in Mongolian.
Jambaldorj said there was much in common between the ancestors of the Mongolians and the Native Americans, adding that some types of stone tools found in the Aleutian Islands had also been discovered in the Gobi desert area of Mongolia.