ST. PETERSBURG, FLORIDA - The Memorial Day weekend marking the unofficial start of summer in the U.S. meant big crowds at beaches and warnings from authorities Sunday about people disregarding the coronavirus social-distancing rules and risking a resurgence of the scourge that has killed nearly 100,000 Americans.

Meanwhile, the White House broadened its travel ban against countries hard hit by the virus by saying it would deny admission to foreigners who have recently been in Brazil.

Sheriff's deputies and beach patrols tried to make sure people kept their distance from others as they soaked up the rays on the sand and at parks and other recreation sites around the country.

In the Tampa area along Florida's Gulf Coast, the crowds were so big that authorities took the extraordinary step of closing parking lots because they were full.

On the Sunday talk shows, Dr. Deborah Birx, coordinator of the White House coronavirus task force, said she was "very concerned" about scenes of people crowding together over the weekend.

"We really want to be clear all the time that social distancing is absolutely critical. And if you can't social distance and you're outside, you must wear a mask," she said on ABC's "This Week."

In Missouri, people packed bars and restaurants at the Lake of the Ozarks, a vacation spot popular with Chicagoans, over the weekend. One video showed a crammed pool where vacationers lounged close together without masks, St. Louis station KMOV-TV reported.

In Daytona Beach, Florida, gunfire erupted Saturday night along a beachside road where more than 200 people had gathered and were seen partying and dancing despite the restrictions. Several people were wounded and taken to the hospital, authorities said.

"Disney is closed, Universal is closed. Everything is closed so where did everybody come with the first warm day with 50% opening? Everybody came to the beach," Volusia County Sheriff Mike Chitwood said at a Sunday news conference, referring to crowds in the Daytona Beach area.

On Georgia's Tybee Island, the beach was filled with families, bicyclists, beach chairs, games, swimmers and more. On a main drag, people lined the sidewalk at Wet Willie's, a chain bar that sells frozen cocktails. Most stood close together - not nearly 6 feet (2 meters) apart - and none wore masks.

But at a nearby grocery store, staff members handed customers gloves and a number to keep track of how many people were inside at a time. Shoppers had their own masks.

Officials in California said most people were covering their faces and keep their distance even as they ventured to beaches and parks. Many Southern California beaches were open only for swimming, running and other activities.

At New York's Orchard Beach in the Bronx, kids played with toys, and people sat in folding chairs. Some wore winter coats on a cool and breezy day, and many wore masks and sat apart from others.

"Good to be outside. Fresh air. Just good to enjoy the outdoors," said Danovan Clacken, whose face was covered.

The U.S. is on track to surpass 100,000 coronavirus deaths in the next few days, while Europe has seen over 169,000 dead, according to a tally by Johns Hopkins University that almost certainly understates the toll. Worldwide, more than 5.4 million people have been infected and nearly 345,000 have died.

The New York Times marked the horror by devoting Sunday's entire front page to a long list of names of those who have died in the United States. The headline: "An Incalculable Loss."

Meanwhile, President Donald Trump, who went golfing for the second day in a row after not playing for weeks, said on the syndicated Sunday program "Full Measure With Sharyl Attkisson" that he is feeling fine after a two-week course of the unproven drug hydroxychloroquine and a zinc supplement.

The president has spent weeks pushing the drug against the advice of many of his administration's top medical professionals. Hydroxychloroquine can have deadly side effects.

The issue of wearing masks in public and staying several feet apart has become fraught politically, with some Americans arguing such rules violate their rights.

Republican Gov. Mike DeWine of Ohio, who has been targeted by such demonstrations, insisted the precautions should not be a partisan issue.

"This is not about whether you are liberal or conservative, left or right, Republican or Democrat," DeWine said on NBC's "Meet the Press." "Its been very clear what the studies have shown, you wear the mask not to protect yourself so much as to protect others."

Critics chided Democratic Gov. Ralph Northam, who has repeatedly urged Virginians to cover their faces in public, for not heeding his own words when he posed mask-less for photographs with residents this weekend. A spokeswoman for the governor's office said that Northam should have brought a mask out with him - but that he hadn't been expecting to be near anyone.

On Sunday, the Trump administration added Brazil to the list of countries it has banned travel from. Brazil is second only to the U.S. in reported coronavirus cases.

The ban, which takes effect Thursday, applies to foreign nationals who have been in Brazil in the 14 days before they hoped to enter the United States. It does not apply to U.S. citizens or legal permanent residents or some of their relatives.

Across Europe, meanwhile, a mishmash of travel restrictions appears to be on the horizon, often depending on what passports visitors carry.

Beginning Monday, France is relaxing its border restrictions, allowing in migrant workers and family visitors from other European countries. Italy, which plans to open regional and international borders on June 3 in a bid to boost tourism, is only now allowing locals back to beaches in their own regions with restrictions.

For the first time in months, the faithful gathered in St. Peter's Square for the traditional Sunday papal blessing, but they kept their distance from one another. Some 2,000 Muslims gathered for Eid al-Fitr prayers at a sports complex in a Paris suburb, spaced 3 feet (1 meter) apart and wearing masks.

Beachside communities in England urged Londoners and others to stay away after rules were eased to allow people to drive any distance for exercise or recreation. The southern coastal city of Brighton said: "Wish you were here - but not just yet." Wales kept up its "Later" tourism campaign, reminding people that its hotels, restaurants and tourist sites are still closed.