The U.S. government's growing indebtedness could put upward pressure on borrowing costs, Dallas Federal Reserve Bank President Richard Fisher said on Monday.

Fisher told a group of bankers and business executives that he was surprised at how low rates have remained despite what he termed a significant increase in debt issuance.

Rates are lower than I would have expected them to be, Fisher said. We'll see how long that continues.

Fisher said the economic recovery would likely be slow, adding that the originally reported 3.5 percent rate of annualized gross domestic product growth for the third quarter would likely be revised lower.

I'm willing to venture that growth was not as robust as originally reported, Fisher told a group of executives at a Texas conference.

He added that revisions would probably bring the annualized growth rate of gross domestic product closer to 2.5 percent or a little bit above that.

(Reporting by Pedro Nicolaci da Costa, Editing by Chizu Nomiyama)