U.S. sovereign bonds rallied on Monday, ahead of a U.S. Federal Reserve monetary policy decision on Wednesday.
Thirty-year Treasury bonds yields also fell to 2.736 percent, after closing at 2.747 percent last week.
U.S. stocks finished mixed on Monday as oil prices fell.
The Fed is expected to hold interest rates on Wednesday and Fed Chair Janet Yellen will provide explanation at her post-meeting press conference.
No major economic data are due on Monday.
U.S. bond yields rose on Friday after European Central Bank President Mario Draghi suggested there would be no further cuts to negative euro zone interest rates.