U.S. government debt prices were lower on Monday as investors digested fresh economic data.
The yield on the benchmark 10-year Treasury notes, which moves inversely to price, was higher at around 2.173 percent, while the yield on the 30-year Treasury bond was also higher at 2.833 percent.
Treasurys
In economic news, the IHS Markit U.S. services PMI for May came in at 53.6, up from 53.1 in April, marking "the largest rise in overall activity since February," IHS said in a release.
The May ISM nonmanufacturing index, meanwhile, came in at 56.9, just below a consensus estimate of 57.0.
Overseas, German benchmark government bond yields nudged up on Monday but did not venture far from one-month lows, with bond investors confident that the European Central Bank will this week only take baby steps towards unwinding its extraordinary stimulus.
The ECB, which meets on Thursday, is set to take a more benign view of the economy and will even discuss dropping some of its pledges to ramp up stimulus if needed, sources with direct knowledge of the discussions told Reuters last week.
An improving economy and some fading of euro zone political risks following French presidential elections in April and May have boosted speculation about a scaling back or "tapering" of the ECB's massive asset-purchase scheme in coming months.
But with the ECB expected to strike a cautious tone because of doubts around inflation, bond investors seem largely unruffled.
In oil markets, prices slipped amid rising tensions in the Middle East in which Arab states, including top crude exporter Saudi Arabia, coordinated to sever ties with Qatar.
Brent crude traded at around $49.51 a barrel on Monday, down 1.04 percent, while U.S. crude was around $47.3622 a barrel, down 0.63 percent.
—CNBC's Fred Imbert and Reuters contributed to this report.