A 2015 study by the Federal Reserve in which 47 per cent of respondents said they couldn't cover a US$400 emergency expense correlates with the AP-NORC result.

Two-thirds of Americans would have difficulty coming up with the money to cover a US$1000 (NZ$1500) emergency, according to an exclusive poll released on Thursday.

It's a signal that despite years after the Great Recession, Americans' finances remain precarious as ever.

These difficulties span all incomes, according to the poll conducted by The Associated Press-NORC Centre for Public Affairs Research.

123RF Caroline Ratcliffe has commented that "lack of savings can lead to homelessness, or other problems.''

Three-quarters of people in households making less than US$50,000 a year and two-thirds of those making between US$50,000 and US$100,000 would have difficulty coming up with US$1000 to cover an unexpected bill.

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Even for the country's wealthiest 20 per cent, households making more than US$100,000 a year, 38 per cent say they would have at least some difficulty coming up with US$1000.

"The more we learn about the balance sheets of Americans, it becomes quite alarming,'' said Caroline Ratcliffe, a senior fellow at the Urban Institute focusing on poverty and emergency savings issues.

Mitchell Timme, 26, said that his wages have remained flat for the last few years while his cost of living has increased.

Once everything is paid "there's nothing left to save," he said.

"It definitely adds stress to everyday life. It hangs over you. While it's not something you would complain about every day, it's there. And it weighs on you,'' Timme said, who works at a security company in Phoenix.

AP-NORC poll: reveals having emergency funds is critical

Having a modest, immediately available emergency fund is recognised as critical to financial health.

Families that have even a small amount of non-retirement savings, between US$250 and US$749, are less likely to be evicted from their homes and less likely to need public benefits, an Urban Institute study found.

"People are extremely vulnerable if they don't have savings,'' Ratcliffe said. "And it's a cost to taxpayers as well. Lack of savings can lead to homelessness, or other problems.''

Despite an absence of savings, two-thirds of Americans said they feel positive about their finances, according to survey data released Wednesday by AP-NORC, a sign that they're managing day-to-day expenses fine.

The challenge for many often comes from economic forces beyond their control such as a dip in the stock market that threatens their job or an unexpected medical bill.

When faced with an unexpected US$1000 bill, a majority of Americans said they wouldn't be especially likely to pay with money on hand, the AP-NORC survey found.

A third said they would have to borrow from a bank or from friends and family, or put the bill on a credit card. Thirteen per cent would skip paying other bills, and 11 per cent said they would likely not pay the bill at all.

Those numbers suggest most American families do not have at least US$1000 stashed away in a savings account, much less under their mattresses, to cover an emergency.

Americans' struggle to save isn't new.

Three CBS News and The New York Times polls going back more than 20 years show a majority of Americans would have difficulty covering a US$1000 emergency.

AP-NORC poll: on retirement

The AP-NORC results also correlate with a 2015 study by the Federal Reserve in which 47 per cent of respondents said they either could not cover a US$400 emergency expense or would have to sell something or borrow money.

And the struggle impacts retirement savings as well.

When AP-NORC asked if they will have enough savings to retire when they want to, 54 per cent of working Americans say they are not very or not at all confident they will have enough.

Only 14 per cent say they are confident they can retire on time.

AP-NORC poll: on presidential election

The AP-NORC findings illuminate how many Americans' frustrations over the economy, income inequality and financial insecurity has contributed to this dizzying presidential election.

Billionaire businessman Donald Trump became the presumptive nominee for the Republican Party largely on a populist platform and a promise to "Make America Great Again.''

On the left, socialist Senator Bernie Sanders of Vermont captured voters with a message of dismantling Wall Street and higher taxes on the rich.

Why don't Americans save?

The reasons why Americans don't save are complex.

One economist says it's a holdover from the 70s and 80s, when high inflation ate into the value of money stashed in a savings account. Others say US tax policy rewards saving money for retirement or taking out a mortgage over short-term emergencies.

When asked to comment on the poll's findings, the White House said "there is still more to do'' to help Americans be more secure at times financial stress.

The Great Recession and lack of wage growth in recent years have not helped.

In the same AP-NORC poll, 46 per cent of workers said their wages have remained stagnant in the last five years, and another 16 per cent said they've seen salary cuts.

Meanwhile, costs for basic needs, such as food, housing and health care, have risen.

"Many families are still struggling with debt from the housing bubble and borrowing boom. And the recent economic stresses make it much more likely families are going to be fighting basic financial issues,'' said William R Emmons, a senior economic adviser at the Centre for Household Financial Stability at the Federal Reserve Bank of St Louis.