U.S. government bond prices rose Friday ahead of a confidence vote for Greece's embattled prime minister.

The price of the benchmark 10-year Treasury note was up 40.6 cents for every $100 invested. The higher price pushed the yield down to 2.04 percent from 2.06 percent late Thursday.

Investors were nervously watching the political turmoil in Greece, which threatens to unravel Europe's plan to control its debt crisis. Late Friday, Greek Prime Minister George Papandreou's government faces a vote of confidence that could determine whether he stays in office.

Papandreou was involved in discussions with European leaders last week before they unveiled a plan aimed at resolving the European debt crisis.

The yield on the 30-year Treasury fell to 3.09 percent from 3.11 percent late Thursday. Its price rose 84.3 cents per $100 invested.

The yield on the two-year note fell to 0.23 from 0.25 percent.

The three-month T-bill paid a yield of 0.01 percent. Its discount wasn't available.