The US death count from Covid-19 surpassed 600,000 on Tuesday, although authorities hailed progress towards a return to normality as its world-leading vaccination program promised to turn the page on one of the worst health crises in its history.
The United States has racked up by far the largest national death count -- ahead of Brazil and India -- after a heavily-criticized early response to the pandemic, but has since organized among the world's most effective vaccine roll-outs.
Progress against the coronavirus was underlined as New York announced more than 70 percent of adults had received at least one vaccine dose and the last of the state's restrictions could be lifted.
"There's still too many lives being lost," President Joe Biden said, noting that despite the daily number of dead dropping sharply, the continuing loss of life was still "a real tragedy."
"My heart goes out to all those who have lost a loved one," he said, speaking on Monday in Brussels as the Johns Hopkins University tally ticked close to 600,000.
"We have more work to do to beat this virus. And now's not the time to let our guard down. Please get vaccinated as soon as possible."
In New York city -- where more than 33,000 died from Covid -- life took a major step forward as almost all restrictions were lifted.
"We have hit 70 percent vaccination," state Governor Andrew Cuomo said.
"It is the national goal, and we hit it ahead of schedule. What does 70 percent mean? It means that we can now return to life as we know it."
- New variant worries -
The US's massive vaccination campaign has been pushed hard since the authorization of the first vaccines in December, and peaked in April, with up to more than four million shots a day.
But the pace has slowed rapidly since then, and unvaccinated people remain vulnerable to the disease.
Just over 52 percent of the US population, or 174 million people, have received at least one dose of one of the three vaccines authorized in the country, according to health officials.
Biden has set a goal of 70 percent of adults to have received at least one shot by the national holiday of July 4, but the program may fall short of that goal.
The US passed the 500,000 death mark at the end of February, just under four months ago. By comparison, it had only taken one month for the country to go from 400,000 to 500,000 deaths.
Experts are concerned about the recent arrival of the new Delta variant of the disease, which initially appeared in India.
Health authorities are trying to convince more people to get the shot by increasing vaccination sites and helping people access to them in partnership with private companies that can provide transport or childcare.
Some states have even launched lotteries which only vaccinated people can enter, with prizes of up to several million dollars.
