Coronavirus Live Updates: Latest News and Analysis

Trump signs executive measures for pandemic relief, but effects are unclear.

President Trump took executive action this weekend that he said would extend an array of federal pandemic relief, while the United States reached yet another virus milestone: five million cases.

It was not clear, though, what immediate effect the orders he signed would have, if any, or what authority Mr. Trump has to act on his own. Under the Constitution, Congress has control over federal spending, and it appears likely that Mr. Trump’s moves to circumvent Congress will be challenged in court.

Mr. Trump signed the orders — billed as a federal eviction ban, a payroll tax suspension, relief for student borrowers and $400 a week for the unemployed — at a news conference at his private golf club in New Jersey on Saturday. The orders did not include a number of provisions sought in congressional proposals, like aid to small businesses, school systems, and state and local governments.

The action came after two weeks of talks between White House officials and top congressional Democrats failed to reach agreement on a broad relief plan and temporary benefits provided under earlier aid measures expired with no resolution in sight.

Virus cases have surged in recent weeks, particularly in the Sun Belt states and in communities where officials moved quickly to reopen. But the nascent economic recovery from those reopenings has appeared to slow or stall in many areas. And schools across the country are grappling with how and whether to reopen in the fall.

According to a New York Times database, the U.S. leads the world in confirmed cases. Brazil ranks second, with more than three million confirmed cases, and India is third with two million. Public health experts have warned that the actual number of people infected is far greater. Brazil also reached a milestone of 100,000 deaths on Saturday.

At least 161,900 people infected with the virus have died in the U.S. since the pandemic began.

New Zealand, a nation of five million people, reported in March that it had stamped out the virus after strict lockdown measures were implemented, and there has been no community transmission since, according to the country’s Health Ministry.

“It has been 100 days since the last case of Covid-19 was acquired locally from an unknown source,” the ministry said in a statement on Sunday. “No additional cases are reported as having recovered, so there are still 23 active cases of Covid-19 in managed isolation facilities.”

Public life has resumed for many people in the country, as they eat out at restaurants, socialize at bars, and attend sports and cultural events. However, some experts warn that letting down their guard now could lead to future outbreaks.

“Achieving 100 days without community transmission is a significant milestone,” said Dr. Ashley Bloomfield, the country’s top health official, said in a statement on Sunday. “However, as we all know, we can’t afford to be complacent.”

“We have seen overseas how quickly the virus can re-emerge and spread in places where it was previously under control,” he said, “and we need to be prepared to quickly stamp out any future cases in New Zealand.”

Your immune system may already recognize the coronavirus.

Radhika Kumar goes to work every morning hoping to save lives. As a contact tracer for Los Angeles County, her job, at least on paper, entails phoning people who have tested positive for the coronavirus, along with others they may have exposed, and providing them with guidance on how to isolate so as not to infect others.

If that sounds easy, it is not.

To persuade people to cooperate, she has to get them to trust her. She has to convince them that they might be infected, even if they have no symptoms. She has to let people curse at her and hang up, then she has to call them back the next day.

And if she wants them to heed her advice, she has to listen, really listen, to how scared they are that if they stay home from their jobs, they might not be able to feed their families.

“Sometimes it can really get to you,” she said. “The other day I had one young lady, and she was screaming on the phone, ‘You don’t understand — I have three kids. I have to go to work.’”

“I kept calling back and calling back,” Ms. Kumar said. “I’m very relentless like that. I thought about it all night — what am I going to do? I called her again first thing in the morning, and I was so relieved when she picked up.”

Even as officials at the Centers for Disease Control and Prevention continue to tout the effectiveness of contact tracing, and state and local health agencies across the United States deploy new armies of tracers, tracking down everyone with the coronavirus is proving to be a Sisyphean task.

France is imposing a new requirement that people wear face masks outdoors in crowded areas of Paris and other major cities beginning on Monday as the number of coronavirus infections rises at the fastest rate since a national quarantine ended in mid-May.

The country had gotten the number of infections under control, but the pandemic is creeping back, with 2,288 new Covid-19 cases reported on Friday — the third consecutive day of sharp increase. In the Paris Ile-de-France region, the rate of infections reached 2.4 percent on Friday, compared with a 1.6 percent national average.

The rise of new clusters has led the government to warn of the possibility of a second wave of infections in the autumn. In an effort to stem the spread of the virus, masks will now be mandatory for people age 11 and above in high-traffic areas, from the tourist havens of Saint Tropez and Biarritz to Paris’s Seine river, Montmartre and other popular sites, as well as at outdoor food markets and in Paris’s crowded suburbs.

The police will be enforcing the measures — which will be in place for at least a month in Paris and are subject to review in other areas — with a fine of 135 euros ($159).

The authorities are especially concerned about the popularity of “free parties,” that have seen hundreds of young people gather in the Parisien woods and other areas, often without wearing masks.

Wearing a mask in crowded enclosed spaces, including museums, shopping malls and on public transportation, has been compulsory in France since mid-July.

The police attributed the accident to a short circuit in an air-conditioner on the ground floor. After the blaze broke out early Sunday, panicked patients jumped from balconies on the upper floors and several were injured, according to local news media outlets.

After most of India’s coronavirus restrictions were lifted in recent weeks, infections have surged, leading some states to move patients into hotels and other makeshift health facilities. As of Sunday, India’s health ministry had reported more than two million total infections and nearly 45,000 deaths.

Dozens of N.F.L. players are choosing their families’ safety over the game.

Despite surging coronavirus transmission rates around the United States, the N.F.L. contends that its season will begin, as scheduled, on Sept. 10. But 68 players have opted out of playing, according to the league.

They represent a microcosm of N.F.L. rosters: rookies and veterans, practice-squadders and starters, all of whom decided to lessen one risk while absorbing another. To keep themselves and their families safer, they will sacrifice the chance to compete for a Super Bowl, forgo showcasing themselves for more lucrative contracts and, in some cases, cede starting jobs and roster spots that may or may not be there next season.

Half of the players who opted out are offensive and defensive linemen, who are in closest contact with other players during practices and games. Leo Koloamatangi, an offensive lineman on the Jets who opted out, said he was resigned to contracting the virus had he chosen to play.

“Where I play, I’m literally bear-hugging another creature on the other side of the ball every single play,” Koloamatangi, 26, said in an interview. “If that guy has any symptoms, I’m going to get them.” He added, “For myself, I couldn’t take those chances.”

Reporting was contributed by Liz Alderman, David Gelles, Heather Murphy, Stanley Reed, Ben Shpigel, Derrick Taylor, Mark Walker, Katherine J. Wu and Ceylan Yeginsu.