Trump to temporarily suspend U.S. immigration over coronavirus concerns COVID-19 has now left more than 40,000 dead in the U.S.

A global pandemic of the novel coronavirus has now killed more than 168,000 people worldwide.

More than 2.4 million people across the globe have been diagnosed with COVID-19, the disease caused by the new respiratory virus, according to data compiled by the Center for Systems Science and Engineering at Johns Hopkins University. The actual numbers are believed to be much higher due to testing shortages, many unreported cases and suspicions that some governments are hiding the scope of their nations' outbreaks.

Since the first cases were detected in China in December, the United States has become the worst-affected nation, with more than 783,000 diagnosed cases and at least 42,094 deaths.

The number of cases in New York state alone is higher than in any single country outside the U.S.

Monday's biggest developments:

Trump to temporarily suspend U.S. immigration

Fauci warns reopening US too soon could 'backfire'

Over 1,800 inmates test positive at Ohio prison

25 teachers dead in NYC

In NJ, 40% of deaths are from long-term care facilities

Here's how the news developed Monday. All times Eastern.

10:38 p.m.: Trump to temporarily suspend U.S. immigration

Citing "the attack from the Invisible Enemy" of the coronavirus, President Donald Trump said he will temporarily suspend immigration to the U.S.

The president said he would carry out the directive through an executive order.

“In light of the attack from the Invisible Enemy, as well as the need to protect the jobs of our GREAT American Citizens, I will be signing an Executive Order to temporarily suspend immigration into the United States!” Trump announced on Twitter.

9:51 p.m.: LA mayor says "there are hard times ahead"

Los Angeles Mayor Eric Garcetti pleaded with the federal government to help U.S. cities struggling with the coronavirus pandemic in a press conference outlining the city's fiscal situation.

"The federal government needs to step up and help cities, just like they help corporations," Garcetti said. "Don't let America's states and cities die. Step up and bail out America as you're bailing out corporations."

Citing a staggering loss of tax revenue due to the coronavirus, Garcetti said that he, along with other civilian city employees, will take a 10% pay cut through mandatory furlough days, and that many city programs will suffer major cuts.

Underscoring his concerns about the pandemic, the mayor reiterated the initial results of a USC antibody study showing that the infection rate in California is far greater than the number of confirmed cases, and that only a small percentage of those tested have antibodies.

8:10 p.m.: 7 new cases in Milwaukee tied to Wisconsin primary

At least seven new COVID-19 cases in Milwaukee appear to be linked to the Wisconsin primary, the city's health commissioner said Monday.

Dr. Jeanette Kowalik said the infected individuals had voted or worked at one of five polling sites on April 7.

The city currently has 30% of the COVID-19 testing data associated with the day of the primary, Kowalik said. A fuller picture of the election-day spread is expected by the end of the week.

The city plans to notify voters who were potentially exposed.

"There were people that were in line for a very long time to get their vote in, so if you figure out around a range of time when someone was there or in the polling sites or in the line, connected to someone who was an actual case, that's when we would do notifications," Kowalik said.

More than 18,800 people voted at the polls in Milwaukee.

Milwaukee County has the most COVID-19 cases and deaths in Wisconsin, with 2,191 and 132 respectively. The state has nearly 4,500 total confirmed cases and 230 deaths.

7:32 p.m.: Federal government ramping up swab production

The federal government is looking to ramp up the production of swabs and other materials needed for COVID-19 testing.

Speaking at the daily coronavirus task force briefing on Monday, Brad Smith, the director of the Centers for Medicare and Medicaid Services' Innovation Center, said the government is working with the country's largest producer of Q-tips to convert the Ohio company’s assembly line to make more than 10 million swabs a month.

Earlier today, White House trade adviser Peter Navarro told ABC News that the Department of Defense was finalizing negotiations that would use the Defense Production Act to help Maine-based Puritan Medical Products increase its swab production from 3 million to more than 20 million per month.

At the briefing, Smith also said the government is working with Oak Ridge National Lab in Tennessee to ramp up the manufacturing of testings tubes to 40 million a month “over the next several weeks.”

The government has secured more than 17 million lancets for finger pricks, 17 million alcohol swabs, and 650,000 infrared thermometers, Smith said.

6:48 p.m.: Heavy testing shows 3/4 of inmates infected in Ohio prison

Extensive testing at an Ohio state prison shows that nearly three in four inmates are infected with COVID-19, according to Ohio Department of Rehabilitation and Correction data.

Nearly 2,000 inmates have tested positive at Marion Correctional Institution, located about 50 miles north of Columbus.

"Because we are testing everyone -- including those who are not showing symptoms -- we are getting positive test results on individuals who otherwise would have never been tested because they were asymptomatic," officials with the Department of Rehabilitation and Correction said in a statement.

4:50 p.m.: Some Georgia businesses to reopen as soon as Friday

In Georgia, hair salons, nail salons, barber shops, gyms and similar businesses can reopen on Friday, Gov. Brian Kemp said.

He said the state's shelter-in-place order will expire on April 30.

Houses of worship and some restaurants can reopen with strict social distancing guidelines, Kemp said. Elective surgeries can also start up again.

In Georgia, at least 733 people have died from the coronavirus. Over 18,000 people have been diagnosed.

4:30 p.m.: Calif. 'not seeing the downward trend we need' to reopen

With hospitalizations slowing but still increasing, California is "not seeing the downward trend we need to see" in order to talk about reopening, Gov. Gavin Newsom said Monday.

California has reported 1,208 fatalities and over 30,000 confirmed cases of COVID-19.

Newsom said a task force is working on addressing disparities in the ability to get a test in different areas of the state. In Los Angeles anyone with symptoms can get a test, but in Sacramento, many are still having trouble getting a test with multiple symptoms.

Newsom said his goal is to be conducting at least 25,000 tests per day by the end of April, and exponentially increasing that number through May and June.

Tune into ABC at 1 p.m. ET and ABC News Live at 4 p.m. ET every weekday for special coverage of the novel coronavirus with the full ABC News team, including the latest news, context and analysis.

4:10 p.m.: 'Vast majority' of Tennessee businesses to reopen on May 1

In Tennessee, the "vast majority" of businesses in 89 of the state's 95 counties can reopen on May 1, Gov. Bill Lee said.

"We are working directly with our major metropolitan areas to ensure they are in a position to reopen as soon and safely as possible," Lee said in a statement. "Social distancing works, and as we open up our economy it will be more important than ever that we keep social distancing as lives and livelihoods depend on it.”

"Our Economic Recovery Group is working with industry leaders around the clock so that some businesses can open as soon as Monday, April 27," he added.

The governor's administration will work with the remaining six counties -- Shelby, Madison, Davidson, Hamilton, Knox and Sullivan -- "as they plan their own reopen strategies," Lee said.

3:40 p.m.: 25 teachers dead in NYC

In New York City, 63 Department of Education employees have died from the coronavirus as of Friday, the department says.

That includes 25 teachers, two administrators, one guidance counselor and two food service staffers.

New York City schools will be closed for the rest of this school year, with students learning remotely instead. Free meals will remain available for students who need them.

Meanwhile, New York City's transportation department has lost 79 employees to the coronavirus.

“We are heartbroken," said Sarah Feinberg, interim president of MTA New York City Transit. "The loss of life at MTA and other front line agencies is unimaginably tragic."

3 p.m.: In NJ, 40% of deaths are from long-term care facilities

New Jersey Gov. Phil Murphy says he spoke to President Donald Trump about the states' urgent need for money from the federal government.

"We can't wait another minute longer," Murphy said.

The governor also said New Jersey will need a partnership with the federal government for testing, contact tracing and health care infrastructure.

As of Monday, 4,377 people have lost their lives in New Jersey. Of those, 40% are associated with long-term care facilities, said Judy Persichilli, commissioner of the state's Department of Health.

The Andover Subacute and Rehab Centers I and II has had a combined 134 cases and 39 deaths, state officials said. The Veterans Memorial Home in Paramus has 155 cases and has had 39 deaths.

More than 88,000 people have been diagnosed in the state, including 1,594 patients who are on ventilators, Murphy said.

2:25 p.m.: COVID-19 death toll in France tops 20,000

The COVID-19 death toll in France topped 20,000 on Monday, which France's Director of Health Jérôme Salomon called "a symbolic and particularly painful milestone."

Of the nation's 20,265 deaths, over 7,000 were in nursing and care homes.

France has over 30,000 patients in hospitals, including 5,683 people in intensive care units.

The U.S., Spain and Italy are the only other countries that have reported more than 20,000 COVID-19 fatalities.

12:15 p.m.: Cuomo calls for hazard pay for front-line workers

New York Gov. Andrew Cuomo is calling for hazard pay for front-line, essential public workers, proposing a 50% bonus.

Cuomo stressed that about 40% of the front-line workers are people of color and one-third are from low-income households.

"The economy did not close down. It closed down for those people who frankly have the luxury of staying at home," Cuomo said. "All of those essential workers, who have had to get up every morning to put food on the shelves, and go to the hospitals to provide health care under extraordinary circumstances ... those people worked. They exposed themselves to the virus."

"After all of that, we see the infection rate among African Americans and brown Americans higher proportionately than other groups. Why? Because they were out there exposing themselves," Cuomo said.

In New York state, 478 lives were lost on Sunday. Twenty-three of those deaths were in nursing homes, Cuomo said.

"We are going through hell," Cuomo tweeted. "When this is all over, I want people to say, we went through hell but we learned lessons and we built a better society because of it."

11:40 a.m.: 40 deaths among NYC homeless

The homeless are especially vulnerable to the coronavirus, and in New York City, at least 40 people experiencing homelessness have succumbed to the virus, according to the Department of Social Services.

Those 40 people are among the 615 homeless individuals who have tested positive for the coronavirus in New York City.

11 a.m.: US, Canada and Mexico agree to keep border closed to nonessential travel for another 30 days

The U.S., Canada and Mexico have agreed to keep their borders closed to nonessential travel for at least another 30 days, Homeland Security officials said Monday.

In addition to the restrictions on legal travel, U.S. Customs and Border Protection is still refusing entry to unauthorized travelers and immediately removing those who cross illegally under an expedited process that largely cuts out the typical administrative review process.

In March, federal authorities deported or "expelled" more than 6,300 unauthorized immigrants from the border "in the interest of public health."

10:05 a.m.: NYC cancels June events including Pride March

In hard-hit New York City, all nonessential permitted events for June -- like parades and concerts -- have been canceled, Mayor Bill de Blasio said Monday.

A lot of these events will be postponed, de Blasio stressed.

Among the annual June events in New York are the Puerto Rican Day parade and the Pride March.

This would have been the 50th anniversary of the LGBTQ Pride March, which the mayor called a "very very big deal."

“Pride is a staple in New York City, and is oftentimes a safe space for many,” David Correa, NYC Pride's interim executive director, said in a statement. “This weighed on our members, board, and staff, knowing that we serve as a haven for vulnerable communities."

"It was not easy to arrive at the decision to cancel pride as we have come to know it over the years, especially given the financial impact this could have on LGBTQIA+ people and businesses, but our top priority remains the health and well-being of all those that participate with us," Correa said.

Data out of New York City appears to be improving, which the mayor called "damn close to what we're looking for."

The number of people admitted to hospitals on Friday was 317, and that fell to 212 on Saturday.

The number of people in intensive care units stayed nearly flat, from 849 Friday to 853 on Saturday.

The percentage of people who tested positive for the coronavirus citywide fell from 38% on Friday to 34% on Saturday.

What to know about coronavirus:

How it started and how to protect yourself: Coronavirus explained

What to do if you have symptoms: Coronavirus symptoms

Tracking the spread in the U.S. and worldwide: Coronavirus map

8:05 a.m.: Fauci warns reopening US too soon could 'backfire'

Dr. Anthony Fauci, one of the nation's top medical experts on the coronavirus pandemic, warned Monday that reopening the U.S. economy too soon could "backfire."

"Unless we get the virus under control, the real recovery economically is not going to happen," Fauci told ABC News chief anchor George Stephanopoulos in an interview on "Good Morning America."

"If you jump the gun and go into a situation where you have a big spike, you're going to set yourself back," he explained. "That's the problem."

Fauci, the director of the National Institute of Allergy and Infectious Diseases, said the United States is currently conducting about 1.5 to 2 million COVID-19 tests per week and is "certainly going to need more."

"We need to get up to at least maybe two times that, three times that," he said. "But we will as we go into the coming weeks."

Fauci noted that tapping into "unused capacity" is equally important, so that states can identify and isolate cases as well as trace contacts.

"What we need to do is make a better connectivity with the tests that are available as well as the capacity that in some cases is not used, through no fault of the governor or the local people," he said. "There's got to be a meeting of the two."

7:21 a.m.: New York state begins coronavirus antibody testing survey

New York state on Monday began conducting antibody tests to help determine how many residents were previously infected with the novel coronavirus.

The testing survey will sample 3,000 people across the state to help determine the percentage of the state's population that has developed the antibodies to fight the virus, potentially allowing more individuals to safely return to work, according to a press release from New York Gov. Andrew Cuomo's office.

Shoppers at grocery stores in different regions of the state will be recruited to participate in the survey, and those who agree will provide a fingerstick blood sample that will be tested at the state-run Wadsworth Center in Albany using its FDA-approved IgG immunologic test.

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said the antibody tests cannot detect whether an individual is currently infected with the virus and the immunity aspect is still unclear.

"There's an assumption -- a reasonable assumption -- that when you have an antibody that you are protected against reinfection, but that has not been proven for this particular virus," he told ABC News in an interview Monday on "Good Morning America."

"We don't know how long that protection -- if it exists -- lasts," he added. "Is it one month, three months, six months, a year?"

Fauci also warned that many of the antibody tests on the market still "need to be validated and calibrated."

"We still have a way to go with them," he said.

6:54 a.m.: Over 1,800 inmates test positive for COVID-19 at Ohio prison

More than 1,800 inmates housed at a single Ohio prison have contracted the novel coronavirus, according to state officials.

At least 1,828 inmates and 109 staff members at the Marion Correctional Institution in Marion, Ohio, have tested positive for COVID-19, according to the Ohio Department of Rehabilitation and Corrections.

Earlier this month, Ohio Gov. Mike DeWine confirmed that a 55-year-old corrections officer at the same facility had died from the disease.

Overall, the Ohio Department of Rehabilitation and Corrections has reported 2,400 positive cases of COVID-19 inside its prisons, according to Columbus ABC affiliate WSYX.

5:38 a.m.: UN confirms death of Nigerian aid worker from COVID-19

An aid worker on the front lines of the novel coronavirus outbreak in Nigeria has died after contracting the virus, a United Nations official confirmed Monday.

Edward Kallon, the U.N. humanitarian coordinator in Nigeria, said a Nigerian man working as a nurse in the country's war-torn Borno state had died over the weekend. It's believed to be the first COVID-19 death in the northeastern state.

"Despite the risks, this Nigerian health worker was devoting his life to treating vulnerable internally displaced persons who have lost everything during the conflict raging in the northeast," Kallon said in a statement. "He had no travel history outside of Borno state and made the ultimate sacrifice."

Kallon noted that officials are working to trace anyone whom the nurse may have been in contact with in Borno state, where nearly 1.5 million of people have been displaced from their homes in recent years due to violence from the Boko Haram insurgency and other conflicts.

"The humanitarian community reaffirms it is working closely with Nigerian authorities. Together, all actors are doing their utmost to reinforce protection and prevention measures against COVID-19," he said. "With the COVID-19 pandemic affecting many areas in Nigeria, it is essential for the most vulnerable to continue receiving humanitarian aid, including water and soap or substitute solutions."

So far, 627 people have been diagnosed with COVID-19 in Nigeria and 21 of them have died, according to a count kept by Johns Hopkins University.

3:45 a.m.: US death toll tops 40,000 as stay-at-home protests continue

The novel coronavirus has now killed more than 40,000 people in the United States, according to a count kept by Johns Hopkins University.

Nearly half of all deaths -- over 18,000 -- occurred in New York state.

Meanwhile, opposition to stay-at-home orders has continued to build from coast to coast amid growing resentment against the crippling economic cost of confinement. Protests took place over the weekend in at least five states -- Colorado, Florida, Illinois, Tennessee and Washington. Last week, other stay-at-home protests took place in California, Kentucky, Michigan, Minnesota, North Carolina, Ohio, Utah and Virginia.

Many of the demonstrations flout the social distancing guidelines put in place by the White House to stem the spread of the virus. Nevertheless, President Donald Trump has spoken out in support of the protesters, describing them as "great people" who "love our country" and "have got cabin fever."

"Their life was taken away from them," Trump said at a press briefing Sunday. "They want to get back to work."

ABC News' Matt Fuhrman, Josh Hoyos, Aaron Katersky, Quinn Owen and Christine Theodorou contributed to this report.