More than 450 scholars from around the world have signed an open letter that calls on Japan to address issues of its wartime past "with both words and action."

The letter, first issued on May 5 and signed by 187 scholars, received "overwhelmingly positive support" among Japan Studies scholars worldwide, Mark Selden, a senior research associate at Cornell University, said in an online post Tuesday.

"This year presents an opportunity for the government of Japan to show leadership by addressing Japan's history of colonial rule and wartime aggression in both words and action," said the letter.

The letter also urges Japanese Prime Minister Shinzo Abe to " act boldly" on historical issues raised during his speech before a joint session of the U.S. Congress on April 29.

In the speech, Abe claimed that Japan started out its path after World War II "bearing in mind feelings of deep remorse over the war," but he fell short of issuing an apology of Japan's wartime atrocities, especially with regard to the so-called " comfort women" issue.

In the open letter, the scholars said "problems of historical interpretation pose an impediment" to celebrating seventy years of peace after WWII, adding that denying or trivializing what happened to former "comfort women" is "unacceptable".

"The evidence makes clear that large numbers of women were held against their will and subjected to horrific brutality," it said.