The U.S. saw a rise in unemployment in 18 states and the District of Columbia in August, with Nevada having the highest unemployment rate at 9.5 per cent, according to the Bureau of Labor Statistics, which released its regional employment figures Friday.

As reported earlier this month, the national unemployment rate in August was 7.3 per cent, one-tenth of a percentage point down from July and and 0.8 percentage points lower than a year ago.

Fifteen states had jobless rates that were significantly lower than that while 11 states and the District of Columbia had "measurably higher rates," the bureau said.

The national rate is the lowest it's been in five years, but the Labor Department warned earlier this month when it released the first set of employment statistics for August that the drop was because more Americans stopped looking for work and were no longer counted as unemployed.

The proportion of Americans working or looking for work is at its lowest level in 35 years.

Dakotas have lowest unemployment rates

North Dakota had the country's lowest jobless rate in August, at only three per cent, followed by South Dakota, at 3.8 per cent. Illinois had the second-highest rate after Nevada at 9.2 per cent. Nevada saw its rate improve from a year ago, when it stood at 11 per cent.

Overall, 17 states saw their unemployment rate drop between July and August while in 15 states the rate remained unchanged.

When compared with a year ago, 36 states and the District of Columbia saw their unemployment rate improve, 12 states saw it increase and two states saw no change at all.​

Generally, the western part of the country continued to have the highest regional unemployment rate, at eight per cent, while the south had the lowest rate, at 7.2. per cent, but the rates were relatively unchanged from July.

New York, California see biggest job gains

Non-farm payroll employment increased in 29 states in August, decreased in 20 states and the District of Columbia and was unchanged in Montana. New York state added 30,400 jobs, the largest month-to-month increase, followed by California, which added 29,100 jobs.

The largest July-to-August decreases in employment were in Georgia, which lost 16,100 jobs, and Ohio, which shed 8,200.

Compared with a year earlier, 34 states had "statistically significant" improvements in employment, according to the bureau, with Texas (up by 274,700), California (up by 223,900) and Florida (up by 131,400) registering the biggest job gains.

Outgoing U.S. Federal Reserve chairman Ben Bernanke said earlier this week that he wants to see clearer signs of labour market improvement and economic before he starts tapering the $85-billion US a month bond-buying program that has been sustaining the U.S. economy.