"There could be selling by Japanese investors on the long end," said Kim Rupert, managing director of global fixed income, at Action Economics in San Francisco.
Japanese investors tend to sell foreign bonds and repatriate the proceeds ahead of their fiscal year end in an effort to bolster their balance sheets.
Analysts also said heavy corporate bond issuance this week as well as in upcoming weeks has also been a factor in the Treasuries' sell-off.
It has been a busy week for the investment-grade market, with 18 deals priced so far this week. Tighter credit spreads and a relatively stable stock market have contributed to the market.
Analysts said the overall bias of the market has been for higher Treasury yields amid what is known as "rate-lock selling" during an expected heavy corporate issuance calendar.
Wall Street dealers typically lock in borrowing costs for corporate bonds they are underwriting by selling Treasuries as a hedge before the deal is completed. Once the bond is sold, the dealer buys back Treasuries to exit the rate lock.
Aside from corporate supply, the market has also been able to absorb $78 billion in US Treasury debt this week, and there has been a little bit of aftereffect from that. Investors tend to sell Treasuries going into these auctions in order to secure a lower price when the sale begins.
In afternoon trading, US 10-year note prices fell, as yields rose to 2.628 percent from 2.610 percent late on Wednesday.
US 30-year bond yields were up at 3.044 percent from 3.01 percent on Wednesday.
On the short end, US 2-year yields advanced to 2.462 percent, compared with Wednesday's 2.453 percent.
Also on Thursday, British lawmakers voted overwhelmingly to seek a delay in Britain's exit from the European Union, setting the stage for Prime Minister Theresa May to renew efforts to get her divorce deal approved by parliament next week.
"The possible delay in Brexit takes away some of the uncertainty and adds the possibility of ending up having another referendum and possibly staying in," said Ellis Phifer, market strategist, at Raymond James in Memphis, Tennessee.
Meanwhile, data showing a rise in US weekly jobless claims and a sharp decline in new home sales had minimal impact on Treasuries, but they do support expectations that the Federal Reserve will hold interest rates throughout the year.