U.S. government bond prices are sharply higher after the Greek prime minister said he would put Europe's rescue plan for Greece to a popular vote.

In Tuesday afternoon trading, the price of the benchmark 10-year Treasury note is up 71.8 cents for every $100 invested. The higher price pushed the yield down to 2.03 percent from 2.16 percent late Monday.

Stocks fell sharply around the world Tuesday. Traders moved money into the U.S. dollar, Treasurys and other assets considered safe. The Greek vote threatens to unravel a plan aimed at resolving the European debt crisis, which European leaders unveiled just last week.

In other Treasury trading, the 30-year bond jumped $2.34, which sent its yield down to 3.22 percent from 3.38 last Friday.