The yield on 10-year Treasuries stood at 1.72 percent, steady from late U.S trading on Tuesday.
Yields on 30-year Treasuries rose to 2.92 percent from 2.90 in late U.S trading on Tuesday.
Japanese shares rose, and the MSCI index of Asia-Pacific shares outside Japan hit a 5-1/2 month peak.
"US earnings have been better than some expected, but the outlook for the US economy is still unclear, so benchmark bonds haven't moved out of this month's range, even with the risk rally," said a fixed-income fund manager at a Japanese asset management firm.
"The US presidential debates don't seem to be having a major impact, either, because the election is still three weeks away, and a lot can happen in the meantime," he added.
US President Barack Obama and Republican challenger Mitt Romney held their second debate on Tuesday, during the Wednesday morning session in Asian trading.
Treasuries fell in US trade on Tuesday as strong earnings from Goldman Sachs and talk of E.U.aid for Spain spurred investors to take on more risk.
Rating agency Moody's Investors Service on Tuesday affirmed its investment-grade sovereign rating of Baa3 on Spain, adding to the positive sentiment.
A German ZEW survey that suggested improving confidence also boosted risk appetite.