http://www.bloomberg.com/apps/news?pid=20601087&sid=aFgHlh.Dn4Lc&refer=home Dec. 24 (Bloomberg) -- Japan should write-off its holdings of Treasuries because the U.S. government will struggle to finance increasing debt levels needed to dig the economy out of recession, said Akio Mikuni, president of credit ratings agency Mikuni & Co.