Many poorer Americans will struggle to retain a foothold in the banking system due to the coronavirus pandemic after years of increasing access, a US banking regulator said on Monday.

A new report from the Federal Deposit Insurance Corporation found that in 2019, just 5.4% of Americans lacked a checking or savings account, the lowest level recorded in the decade-long survey.

However, the watchdog warned that the economic harm wrought in 2020 by the pandemic could do the most damage to people barely able to access traditional banking services.

"The Covid-19 pandemic is likely to contribute to a rise in the rate of unbanked households," the FDIC said in its report, noting that banking access is usually directly tied to economic gains.

"The regulator said it could not predict how many people would lose access to bank accounts or otherwise suffer economically, but noted some concerning signs. In 2019, 35.8% of households reported not saving for unexpected expenses or emergencies.

"Among unbanked populations, 74% were not able to build up emergency savings."