Travelers wearing face masks are seen at Ronald Reagan Washington National Airport in Arlington, Virginia, the United States, on Dec. 23, 2020. (Photo by Ting Shen/Xinhua)

"Experts have long argued that the US's public health infrastructure is underresourced and ill prepared for a serious crisis, and the pandemic has exposed this many times over: Nearly a year into the pandemic, no state has capacities for testing and contact tracing that most experts would consider adequate," said Vox's German Lopez.

WASHINGTON, Jan. 19  -- The number of confirmed COVID-19 deaths in the United States surpassed the grim milestone of 400,000 on Tuesday, the last full day of Donald Trump's presidency.

100,000 DEATHS JUST OVER A MONTH

With the national confirmed cases topping 24.18 million, the death toll across the country rose to 400,292 as of 3:22 p.m. local time on Tuesday, according to a tally by Johns Hopkins University (JHU).

New York State reported 41,350 fatalities, at the top of the U.S. state-level death toll list. California recorded the second most deaths of 33,763, followed by Texas with 32,729 deaths and Florida with 24,274 deaths, showed the JHU data.

States with more than 12,000 fatalities also include New Jersey, Illinois, Pennsylvania, Michigan, Massachusetts and Georgia.

The saddening milestone came just over a month after the U.S. COVID-19 death toll topped 300,000 on Dec. 14. It took nearly four months for the national death toll to climb from 100,000 to 200,000, and less than three months to jump from 200,000 to 300,000.

The richest country in the world remains the worst hit by the pandemic, accounting for more than 25 percent of the global cases and nearly 20 percent of the global deaths.