LOS ANGELES >> The average long-term U.S. mortgage rate climbed this week to its highest level since November, driving up borrowing costs for would-be homebuyers at a time when the housing market is being held back by a near record-low inventory of homes on the market.

Mortgage buyer Freddie Mac said Thursday that the average rate on the benchmark 30-year home loan rose to 6.79% from 6.57% last week. A year ago, the rate averaged 5.09%.

The latest increase marks the third in three weeks and lifts the average rate on a 30-year home loan to its highest level since it surged to 7.08% in early November.

The average rate on 15-year fixed-rate mortgages, popular with those refinancing their homes, rose to 6.18% this week from 5.97% last week. A year ago, it averaged 4.32%, Freddie Mac said.

High rates can add hundreds of dollars a month in costs for homebuyers, limiting how much they can afford in a market that remains unaffordable to many Americans after years of soaring home prices and historically low levels of housing inventory.

Mortgage rates have ticked higher along with the 10-year Treasury yield, which lenders use as a guide to pricing loans. The yield hit 3.81% last week, its highest point since early March, reflecting uncertainty among bond investors over whether the federal government would be able to avoid a debt default and renewed worries that the Federal Reserve may not be done hiking interest rates.

“Mortgage rates jumped this week, as a buoyant economy has prompted the market to price-in the likelihood of another Federal Reserve rate hike,” said Sam Khater, Freddie Mac’s chief economist. “Although there has been a steady flow of purchase demand around rates in the low- to mid-6% range, that demand is likely to weaken as rates approach 7%.”

The House of Representatives approved a deal on Wednesday to prevent a possible default on the U.S. government’s debt. But uncertainty over what the Fed will do at its upcoming interest rate policy meeting this month, and beyond, could keep the bond market on edge, driving more mortgage rate volatility.

Investors’ expectations for future inflation, global demand for U.S. Treasurys and what the Fed does with interest rates influence rates on home loans.