With the US dealing with the worst coronavirus outbreak in the world, Florida hit a grim milestone on Sunday as it broke the national record for a state's largest single-day increase in positive cases.
A long-expected upturn in deaths has begun across the country, driven by fatalities in states in the south and west.
They are still well below the heights hit in April, however, according to a recent Associated Press analysis of data from Johns Hopkins University.
Brett Giroir, a member of the White House coronavirus task force, called mask wearing in public, which has been met with resistance in some US states, "absolutely essential".
Mr Giroir, the assistant secretary at the Health and Human Services Department, told ABC's This Week on Sunday that "if we don't have that, we will not get control of the virus".
President Donald Trump wore a mask in public for the first time on Saturday, something Democratic House Speaker Nancy Pelosi said showed he has "crossed a bridge".
Ms Pelosi told CNN's State of the Union that she hopes it means the president "will change his attitude, which will be helpful in stopping the spread of the coronavirus".
Researchers expect deaths to rise in the US for at least some weeks but some think the count probably will not go up as dramatically as it did in the spring because of several factors, including increased testing.
Meanwhile, countries in eastern Europe are also facing rising waves of coronavirus infections, leading to riots in Serbia, mandatory face masks in Croatia and travel bans or quarantines imposed by Hungary.
"We see worrisome signs about an increase in the number of cases in the neighbouring countries, Europe and the whole world," Gergely Gulyas, Hungarian Prime Minister Viktor Orban's chief of staff, said.
"Now, we have to protect our own security and prevent the virus from being brought in from abroad."
Hungarian authorities said they have sorted countries into three categories – red, yellow and green – based on their rates of new coronavirus infections and will impose restrictions.
These include entry bans and mandatory quarantines, depending on which country people are arriving from.
Serbia, where health authorities are warning hospitals are almost full due to the latest surge, reported 287 new infections on Sunday, although there have been increasing doubts about the accuracy of the figures.
Officially, the country has more than 18,000 confirmed infections and 382 deaths since March.
Sunday's report of 11 coronavirus deaths was the country's second-highest daily death toll.
Serbian police clashed with anti-government protesters for four nights last week, demonstrations that forced the president to withdraw plans to reintroduce a coronavirus lockdown.
Many of the increasing infections have been blamed on crowded football matches, tennis events and nightclubs.
In Bulgaria, authorities reintroduced restrictions lifted a few weeks ago because of a new surge in cases.
Albania also has had a significant increase in infections since mid-May, when it eased lockdown measures.
The Balkan nation reported 93 new cases, over twice as many as the highest daily figures in March and April, and the health ministry called the situation at the main infectious disease hospital "grave".
Croatia is making wearing masks mandatory in stores from Monday.
Yet the numbers of infections in eastern Europe pale in comparison to daily coronavirus reports from India, South Africa and Brazil, whose president has tested positive for the disease.
India, which has the most cases after the US and Brazil, had a record surge of 28,637 cases reported in the past 24 hours.
Authorities have announced a week-long lockdown beginning on Tuesday in the key southern technology hub of Bangalore.
South Africa has reported more than 10,000 new daily cases for several days in a row, including 13,497 new infections announced on Saturday night.
Meanwhile, in Taiwan, which kept its coronavirus outbreak to a few hundred cases, an annual film festival wrapped up with an awards ceremony this weekend where actors and others lined up for photo shoots with no social distancing, and participants didn't wear masks.