Many analysts and investors expect that the Fed will announce that it will begin reducing its bond portfolio at its September meeting, but will be watching for any new hints of the timing at this week's meeting.
Further interest rate hikes are not seen as likely until December. Futures traders are pricing in a 47-percent chance that the Fed will raise rates at its December meeting, according to the CME Group's FedWatch Tool.
Data this week including Gross Domestic Product for the second quarter due on Friday will also be a key focus, while the Treasury Department is also due to sell $88 billion in short- and intermediate-dated coupon-bearing supply this week.
These factors are likely to weigh on Treasuries, which have rallied in the past two weeks on what analysts said are mainly technical factors.
"Momentum that had been oversold is shifting increasingly to overbought, which sets this week up to be about the data and about the Fed," said Ian Lyngen, head of US rates strategy at BMO Capital Markets in New York.
Benchmark 10-year notes were last down 4/32 in price to yield 2.25 percent, up from 2.23 percent on Friday. The yields have fallen from 2.40 percent on July 7.
The Treasury on Monday will auction $39 billion in three-month Treasury bills that are due to mature on Oct. 26, which will be scrutinized after similar auction last week saw tepid investor demand.
Investors are concerned that payments on debt due in October may be delayed if efforts to raise the debt ceiling come down to the wire.
Disagreements among Republicans on healthcare legislation show a lack of consensus among lawmakers, which could make budget negotiations equally acrimonious.
The Congressional Budget Office said last month that Congress would need to raise the debt limit by early to mid-October to avoid a default.
Yields on three-month Treasury bills, which are due to mature on Oct. 19, briefly rose to 1.174 percent on Monday, the highest level since Oct. 2008.
The Treasury Department will also sell $26 billion in two-year notes on Tuesday, $34 billion in five-year notes on Wednesday and $28 billion in seven-year notes on Thursday.