US Treasurys rally on 'Grexit' worries

U.S. government debt prices rallied on Monday, pushing yields lower as traders focused on tensions between Greece and its euro zone partners in their debt negotiations.

The 10-year benchmark Treasury note yield fell to 1.93 percent after closing at 1.938 percent on Friday. Thirty-year bond yields traded lower at 2.50 percent Friday after closing at 2.518 percent on Friday.

US 10-YR
US 30-YR

Greek Prime Minister Alexis Tsipras said his election pledge to end austerity by restructuring Greece's debt was "irrevocable" in his inaugural speech in parliament late Sunday.

Greek bonds sold off following the speech, with the short-end of the market hit hardest. Greek two-year bonds soared to yield 20.7 percent, while five-year and 10-year yields climbed to trade around 16 percent and 11 percent respectively.

Read MoreDefiantGreek leader gets set for a EU clash

Last week's strong jobs report has also made investors jittery as the improvements in the labor market could increase potential for an early interest rate hike from the U.S. Federal Reserve.

The U.S. economy added a better-than-expected 257,000 jobs in January, according to data from the Bureau of Labor Statistics Friday.

The consensus forecast for nonfarm payrolls in January is 230,000, while the unemployment rate is expected to remain unchanged at 5.6 percent.

Read MoreG-20 chiefs plea for 'cooler heads' in Greek crisis

The coming week should be a less eventful one for economic data, with no major releases due Monday. Major data expected later in the week includes January's retail sales figures, due on Thursday.