California has overtaken New York as the US state with the most coronavirus fatalities during the pandemic, reflecting the impact of a months-long surge in cases and hospitalisations.

On Saturday, California's health department attributed a further 669 fatalities to coronavirus, which took the overall number of confirmed deaths in the most populous US state to 32,960. New York's overall death toll reached 32,725 following a further 157 fatalities reported over the past day, according to state data.

New York had been the top-ranked state by coronavirus deaths since late March, having recorded most of its fatalities during the early stage of the pandemic when states in the northeast were hit hardest. California, though, has experienced the worst of its crisis in the past two months. The situation has become particularly dire in Los Angeles, which on Saturday became the first county in the US to surpass more than 1m cases since the start of the pandemic.

Line chart of Highest coronavirus death tolls among US states showing California overtakes New York as the state with the most Covid deaths

Following a record surge in cases and hospitalisations that have stretched emergency and medical resources thin, California has tallied 6,989 coronavirus deaths so far in January, eclipsing the 6,760 for December that made that its deadliest month of the pandemic.

The US has confirmed 383,130 coronavirus deaths since the start of the pandemic, according to the most recent Covid Tracking Project data from Friday. Given the average of about 3,300 deaths a day over the past week, president-elect Joe Biden is set to inherit control of the response to a pandemic that will have claimed more than 400,000 American lives by the time he is inaugurated on January 20.

Mr Biden on Friday pledged to have 100m Americans vaccinated within his administration's first 100 days in office. The president-elect said he would mobilise the Federal Emergency Management Agency to create more vaccination sites, invoke the Defense Production Act to increase supplies of the vaccine and train new workers to administer the jabs as part of a five-point plan to reach his target.

Column chart of Coronavirus fatalities for the main geographic regions of the US showing US coronavirus death toll approaches 400,000

Of the 31.1m vaccines doses that have been distributed in the US, about 10.6m Americans have received at least one shot, according to the Centers for Disease Control and Prevention.

Efforts to accelerate the vaccine rollout across the US could be complicated by the varying approaches of states and impending supply bottlenecks, according to health experts. Leaders in New York homed in on those issues in recent days. New York City Mayor Bill de Blasio warned the city "will run out of vaccine at some point next week unless we receive a major new resupply", while Governor Andrew Cuomo on Friday said the state's allocation of doses from the federal government was set to drop to 250,00 next week from 300,000 previously.

The race to vaccinate more Americans and contain the pandemic also faces another potential challenge from the new coronavirus variant discovered in the UK, which the CDC predicts could become the dominant strain in the US by March. At least 80 cases of the more infectious strain have been confirmed across more than a dozen states. Public health officials in Los Angeles on Saturday confirmed the county’s first case of the variant.

Coronavirus deaths tend to lag increases in cases and hospitalisations, and there may be some glimmers of hope on the latter. The number of people in US hospitals with coronavirus fell to a 12-day low of 127,235 according to Friday data from Covid Tracking Project, and is down 4 per cent from a record high earlier this month.

California on Saturday reported an additional 40,622 coronavirus cases, taking its total since the start of the pandemic over 2.9m for the first time and more than any other state. New York added almost 16,000 infections to bring its tally to 1.22m, which ranks fourth in the US after California, Texas and Florida.

Adjusted for population, California’s death toll equates to about 83 fatalities per 100,000 people, which is among the 15 lowest for states, according to a Financial Times analysis of Covid Tracking Project data. That is less than half New York’s rate of about 168 deaths per 100,000 people that is the ninth-highest in the US.