The number of academics who have signed a statement urging Japan to address its wartime past has more than doubled since its publication two weeks ago, a scholar who leads the initiative said Tuesday.

Mark Selden, a senior research associate at Cornell University, said the document has now drawn the support of over 450 academics. When it was first published on May 5, 187 scholars of Japanese studies had signed the statement.

Among the second group of signatories to the statement, titled "Open Letter in Support of Historians in Japan," is Ian Buruma, a Bard College professor who authored "The Wages of Guilt: Memories of War in Germany and Japan."

Alexis Dudden of the University of Connecticut, another scholar leading the campaign, said of the rise in signatures: "goes back to the heart of the open letter about the need to support open discussion in Japan to leave an honest record of its past for current and future generations."

While noting postwar Japan's history of democracy, civilian control of the military and generous aid to other countries, the statement warns that problems with its interpretation of its history before and during World War II "pose an impediment to celebrating these achievements."

Signatories to the document urged Japan to address its history of colonial rule and wartime aggression "in both words and action" and encouraged Prime Minister Shinzo Abe to acknowledge "past wrongs" in a statement he will deliver this summer to mark the 70th anniversary of Japan's surrender.