WASHINGTON — U.S. job openings rose unexpectedly in August as the American labor market continued to show resilience.

The Labor Department reported Tuesday that employers posted 8 million vacancies in August, up from 7.7 million in July. Economists had expected openings to be virtually unchanged. Openings were up in construction and in state and local government.

Layoffs fell in August. But the number of Americans quitting their jobs — a sign of confidence in their job prospects — slid to the lowest level since August 2020 when the economy was reeling from COVID-19 lockdowns.

Job openings have come down steadily since peaking at 12.2 million in March 2022, but they remain above where they stood before the coronavirus pandemic hit the American economy in early 2020. When the economy roared back with unexpected strength from COVID-19 lockdowns, companies scrambled to find enough workers to keep up with customer orders.

The overheating economy caused an outburst of inflation, and the Federal Reserve responded by raising its benchmark interest rate 11 times in 2022 and 2023. Inflation has come down — from a peak of 9.1% in June 2022 to 2.5% in August.

The economy proved surprisingly resilient in the face of the Fed hikes, averting a widely forecast recession. But the job market has gradually lost momentum. Hiring averaged just 116,000 net new jobs a month from June through August — the weakest three-month average since mid-2020.

When the Labor Department releases its jobs report for September on Friday, it is expected to show that employers added 143,000 jobs last month and that the unemployment rate remained at a low 4.2%, according to a survey of forecasters by the data firm FactSet.

The Fed, satisfied with the progress against inflation and worried about the cooling job market, last month cut its benchmark rate by a hefty half percentage point, the central bank’s first and biggest rate cut since March 2020.

“Job openings had a big gain, and while these numbers are volatile, it’s likely employers see falling interest rates spurring the economy and may want to staff up,” said Robert Frick, economist with the Navy Federal Credit Union.