WASHINGTON—Sales of new U.S. single-family homes unexpectedly fell in February amid rising mortgage rates and higher house prices, which are squeezing out some first-time buyers from the market. Despite the second straight monthly decline reported by the Commerce Department on Wednesday, sales remained above their pre-pandemic level. Economists saw reduced affordability curbing activity in the near-term, but expected the new housing market to plod along this year given pent-up demand, a record low inventory of previously owned homes and strong wage gains. “With interest rates climbing further because of the negative supply shock emanating from the Russian invasion of Ukraine, home sales are likely to trend lower in coming months,” said David Berson, chief economist at Nationwide in Columbus, Ohio. “But unless mortgage rates spike or the economy stalls or worse, the falloff in new home sales should be modest.” New home sales decreased 2 percent to a seasonally adjusted …