U.S. Treasuries increased on Tuesday amid speculation that buying at today's $32 billion auction of three-year notes will be boosted by the Bank of Japan's decision to double its assets purchases. The benchmark U.S. 10-year yields decreased by two basis points to 1.73% at 9:31 a.m. in New York after it dropped to the lowest since December 12 at 1.68% on April 5.