Life expectancy fell in the United States in 2021 for the second year in a row to its lowest level since 1996, driven by COVID-19 deaths, according to provisional government data published on Wednesday.

The nearly one-year decline from 2020 to 76.1 years marked the largest two-year drop in life expectancy at birth in close to a century, the U.S. Centers for Disease Control and Prevention (CDC) found.

Disparity in life expectancy between men and women also widened last year to the highest in over two decades, with men now expected to live 73.2 years, nearly six fewer years than women.

Deaths from COVID-19 contributed to half of the overall decline in life expectancy last year, with drug overdoses and heart disease also major contributors, the data showed.

COVID-19 was associated with more than 460,000 U.S. deaths in 2021, according to the CDC.

In 2020, U.S. life expectancy saw its biggest one-year drop since World War Two, with COVID-related deaths contributing nearly 75% to the decline.

"Mortality's been a little better in 2022 than it was in 2020, so I think it's likely that we would see maybe a slight increase in life expectancy," said Robert Anderson, chief of mortality statistics at CDC's National Center for Health Statistics.

However, life expectancy this year will likely not return to pre-pandemic levels, and a lot rides on what happens toward the end of the year as deaths typically rise during winter months, Anderson said.

While deaths from suicide had decreased in 2020, they were the fifth biggest contributor to the drop in overall life expectancy last year. Suicide-related deaths were the third leading contributor of the decline in life expectancy for men.

The data represents early estimates and has several limitations, the agency noted, including the difference in the time taken by various jurisdictions in submitting death certificates.