The unemployment rate in the United States fell to a five-year low of 7.7% in February, the Bureau of Labour Statistics said on Friday, adding to the upbeat mood surrounding the US economy.

News of the decline in joblessness, from 7.9% in January, was expected to produce a strong finish for stocks for the week on Wall Street, while markets in Europe were also up sharply.

A separate survey of employers found that non-farm payrolls grew by 236,000 last month. Growth was reported in the construction and healthcare sectors.

Stronger hiring shows businesses are confident about the economy, despite higher taxes and government spending cuts.

The government's February employment report was filled with mostly encouraging details. Hiring has averaged more than 200,000 per month since November, and wages have increased.

As well, the job gains were broad-based, led by the best construction hiring in six years.

One negative detail: Employers added fewer jobs in January than first estimated. Job gains were lowered to 119,000 from an initially reported 157,000. Still, December hiring was a little better than first thought, with 219,000 jobs added instead of 196,000.

The unemployment rate had been stuck at 7.8% or above since September. About half the decline in February occurred because more of the unemployed found jobs. A decline in the number of people looking for work accounted for the other half. People who aren't looking for jobs aren't counted as unemployed.

Strong auto sales and a steady housing recovery are spurring more hiring, which could lead to stronger economic growth. The construction industry added 48,000 in February and 151,000 since September. Manufacturing has gained 14,000 last month and 39,000 since November.

Optimism about the world's largest economy have pushed stock markets higher this year, with the Dow hitting a string of record highs this week.

The dollar is also rising as investors think the run of positive news may prompt the Federal Reserve to bring an end to its super-loose monetary policy sooner than previously thought.