(Reuters) -A gauge of U.S. homebuilder sentiment slid unexpectedly to its lowest level in two and a half years in June, with more than a third of residential construction firms cutting prices to lure buyers sidelined by high mortgage rates and economic uncertainty due to President Donald Trump's tariffs.

The National Association of Home Builders/Wells Fargo Housing Market Index fell to 32, the lowest reading since December 2022, from 34 in May. Economists polled by Reuters had expected the sentiment score to improve to 36.

Measures of current sales conditions, future sales expectations and buyer foot traffic all fell. On a regional basis, the Northeast posted a small rise while the South, Midwest and West all declined.

"Rising inventory levels and prospective home buyers who are on hold waiting for affordability conditions to improve are resulting in weakening price growth in most markets and generating price declines for resales in a growing number of markets," Robert Dietz, NAHB's chief economist, said in a statement. "Given current market conditions, NAHB is forecasting a decline in single-family starts for 2025."

Mortgage rates remain elevated. The average rate on the most popular home loan, the 30-year fixed-rate mortgage, was 6.84% last week, according to home finance firm Freddie Mac, squarely in the middle of the 6.60% to 7.04% range over the past six months.

"Buyers are increasingly moving to the sidelines due to elevated mortgage rates and tariff and economic uncertainty," said NAHB Chairman Buddy Hughes, a home builder and developer based in Lexington, North Carolina. "To help address affordability concerns and bring hesitant buyers off the fence, a growing number of builders are moving to cut prices."

The survey showed 37% of builders were cutting prices in June, the highest percentage since NAHB began tracking the metric on a monthly basis in 2022. That figure was up from 34% in May and 29% in April, while the average price cut held steady at 5%. The use of any kind of incentive ticked up a point to 62%.