A delay in talks over passing new measures to cut Greece's budget deficit kept demand for Treasurys strong Monday.
The yield on the 10-year Treasury note edged down to 1.90 percent compared with 1.93 percent late Friday. Its price rose 28 cents per $100 invested.
Greece's coalition leaders pushed back a key meeting on the measures by a one day till Tuesday. Greece needs to pass the package before it gets more bailout money from international lenders, which it must have to avoid defaulting on its next bond payment.
In other trading, the yield on the 30-year bond fell to 3.09 percent from 3.12 percent. Its price rose 72 cents per $100. The yield on the two-year note was flat at 0.23 percent.
The three-month T-bill paid a yield of 0.07 percent.
Several auctions of U.S. government debt are coming up this week, which could push prices lower. An auction for three-year notes is coming up Tuesday; 10-year notes will be sold Wednesday and 30-year bonds on Thursday.