CDC Director Robert Redfield said masks are key to stopping the crisis.
The novel coronavirus pandemic has now killed more than 577,000 people worldwide.
Over 13.2 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 or downplaying the scope of their nations' outbreaks.
The United States has become the worst-affected country, with more than 3.4 million diagnosed cases and at least 136,440 deaths.
Saturday appeared to mark the first day since March that there were no COVID-19 deaths in New York City. But the latest data from the city's health department shows that at least eight people with confirmed or probable COVID-19 cases died that day.
The health department's portal does note that "due to delays in reporting, recent data are incomplete." These delays are especially prevalent on weekends.
On Monday, Mayor Bill de Blasio had celebrated the apparent milestone before warning that residents cannot let up the fight against the virus.
The first COVID-19 death in New York City was on March 11. Since then, the city has had more than 23,000 deaths attributed to the virus -- far more than any state.
Washington Gov. Jay Inslee said Tuesday that the return of certain restrictions is possible as COVID-19 cases have grown "fairly dramatically" over the past month.
The pause of the state's reopening will continue until at least July 28, and "people should not be surprised if more gets rolled back," Inslee said during a COVID-19 press briefing.
The governor said there is a "significant chance" that the state will need to take more measures.
"Over a thousand people have died," he said. "A thousand more will die if we do not act."
Washington has 42,304 confirmed cases of COVID-19 and 1,404 deaths, according to the state health department.
One bright spot, the governor said, is Yakima County, where the number of new cases and test positivity rates have declined since a mask mandate went into effect on June 26.
Dr. LouAnn Woodward, vice chancellor of the University of Mississippi Medical Center, told "World News Tonight" on Tuesday that the state is now in the worst of its battle with COVID-19.
"We were a little bit slower or behind New York, behind the West Coast as far as seeing that real surge of patients, but we're seeing our highest numbers of patients as we speak," Woodward said.
On Monday, the number of cases jumped 862 to a total of 37,542. The number is shy of two 1,000-case days in late June, but still overwhelming UMMC.
"We are full. We are full in our med surge beds, we are full in our ICU beds," Woodward said. "As of some hours ago, we had a few open pediatric beds, but in fact in the adult bed count, at this moment, we're oversubscribed by 29."
The crisis in Los Angeles County is continuing to get worse.
The county reported a new daily record for deaths (73) and cases (4, 244) on Tuesday. The county did qualify that the death total could be higher due to a lag in reporting from over the weekend.
There are 2,103 people currently hospitalized in the county, 19% of which are on ventilators.
The county already has rolled back some of its reopening plans in the wake of the rise in cases.
Texas continues to be one of the hotspots for a surge in COVID cases, with a new record 10,745 since yesterday. There were more than 2,000 cases in Harris County -- home to Houston -- alone.
The previous single-day high for cases was 10,351 on July 11.
There were 87 fatalities in the state reported on Tuesday.
Moderna released data from its Phase 1 trial Tuesday, saying the trial was relatively safe and that all 45 people who were given the vaccine developed COVID-19 antibodies.
These antibodies are believed to provide some level of immunization, but how much immunization and for how long is still to be determined.
The trial was made up of three groups with 15 people in each group. Each group received a different dose of the vaccine -- low, medium or high.
Side effects were minimal, Moderna said.
CDC Director Robert Redfield told JAMA on Tuesday, "I really do believe if the American public all embraced masking now and we really did it, you know, rigorously ... I think if we can get everybody to wear a mask right now, I really do think over the next four to six, eight weeks, we can bring this epidemic under control."
"Masking is not a political issue, it is a public health issue," he continued, calling it a "personal responsibility" for everyone.
"I'm glad to see the president wear a mask this week, and the vice president," Redfield said. "We need them to set the example."
Redfield said "the most powerful weapon we have" against the coronavirus is using face coverings, washing hands and "being smart about social distancing."
"If we all rigorously did this, we could really bring this outbreak back to where it needs to be," he said.
In North Carolina, where there are over 89,000 confirmed coronavirus cases, schools will open with in-person and remote learning, Gov. Roy Cooper said Tuesday.
The beginning of the school year in North Carolina is about a month away, he said.
Schools will have protocols in place including fewer children in classrooms, social distancing and required face coverings for all students and staff, Cooper said. The schools are also recommended to use one-way hallways and suspend large group activities like assemblies.
Districts will have the option to conduct all remote learning if that is best for them, he said.
"If trends spike and in-person school cannot be done safely with these safety protocols, then we will need to move to all remote learning like we did in March," Cooper tweeted.
In Philadelphia, large public events will be banned through Feb. 28, 2021, Mayor Jim Kenney announced Tuesday.
Banned events include parades, concerts, fairs and block parties. The ban does not apply to demonstrations and first amendment activities.
People under the age of 30 have accounted for 40% of new cases in the city, the mayor said.
The city is allowing people to hold private outdoor events, like weddings, if there are fewer than 50 guests, the mayor added.
"To bring people together in large groups ... would not be responsible. And that's why we're doing what we're doing," Kenney said at a news conference.
"We're going to have to live with the virus for a long time," said Dr. Thomas Farley, commissioner of the city's Department of Public Health. "We're gonna have to have some restrictions on our activities until we deploy a vaccine."
Philadelphia held a parade during the 1918 flu pandemic, which prompted a massive outbreak.
Farley said that is "still in the memory" of public health workers and "that weighs on all of our decisions."
Philadelphia has over 27,000 cases of the coronavirus. While the city is not facing the same rise in cases many states are seeing, Farley called this a "dangerous period."
"The way for us to avoid similar increases ... is to have everyone follow the safety precautions," he said.
In Arizona, where the pandemic has intensified, the state reported a positivity rate of 20% on Tuesday, a slight drop from the 21.7% rate on Monday. Nationally, the overall test-positivity rate stands at 9.4%, according to a FEMA memo obtained by ABC News.
Arizona reported 4,273 new cases and 92 new deaths on Tuesday, according to the state's Department of Health Services.
The state has 197 adult ICU beds available, the department said. On Monday officials said ICUs were 90% full.
Gov. Doug Ducey said Monday he was expanding testing capacity and limiting indoor dining to 50%.
Out of 309 facilities being tracked, Florida has 48 hospitals with no available ICU beds, and 31 hospitals with just one available ICU bed, according to the state's Agency for Healthcare Administration. These numbers will fluctuate throughout the day.
Hard-hit Florida saw a record new 133 deaths bringing the fatality total to 4,513, the state's Department of Health said Tuesday.
Miami-Dade County, which includes Miami, and Osceola County, home to the cities of Kissimmee and Celebration, are especially hard-hit.
Miami-Dade is reporting a positivity rate of 22.1% while Osceola County's positivity rate stands at 22.8%. Duval County, home to Jacksonville, and Hillsborough County, which includes Tampa, both have positivity rates at 16%.
Minnesota, New Mexico, Ohio and Wisconsin have been added to New York's coronavirus travel advisory, Gov. Andrew Cuomo said Tuesday.
Those four states join Alabama, Arkansas, Arizona, California, Florida, Georgia, Iowa, Idaho, Kansas, Louisiana, Mississippi, North Carolina, Nevada, Oklahoma, South Carolina, Tennessee and Texas. Delaware has been removed from the list.
Travelers headed to New York, New Jersey or Connecticut from those states must quarantine for two weeks.
The quarantine applies to states with a positive test rate higher than 10 per 100,000 residents over a one-week average, or any state with a 10% or higher positivity rate over a one-week average.
Beginning at 12 a.m. Wednesday local time, Hong Kong is returning to stricter social distancing measures after seeing a new surge in cases.
Hong Kong reported over 200 new coronavirus cases in the last week, following nearly a month without a single case.
For at least the next week, Hong Kong is closing bars, gyms, playgrounds, pools and entertainment venues, including Hong Kong Disneyland.
Public gatherings cannot exceed four people.
Masks will be mandatory in taxis and on public transportation -- and those who do not comply can be fined.
Restaurants will be take-out only for dinner while dining in will be permitted for breakfast and lunch.
Also, travelers must show proof of a negative COVID-19 test before boarding a flight to Hong Kong.
Virginia Beach, Virginia, maybe a new spot to watch, according to an internal FEMA memo obtained by ABC News.
Virginia Beach reported 317 new cases for the week ending July 8 -- a 92.1% increase over the previous week.
Montana is also seeing a drastic jump.
On July 9, the state reached a new single-day record of 96 new cases, according to the FEMA memo. There were 377 new cases reported in the week ending July 8 -- a 59.1% increase week-over-week.
Nationally, the overall test-positivity rate stands at 9.4%, according to the FEMA memo.
Forty states reported an upward trend test-positivity rate over the last week.
Nationwide death counts show a large increase in the last two days.
From July 6 to July 12, there were 410,332 new cases reported and 5,073 new deaths in the U.S. Those figures represent a 20.4% increase in cases and a 47.4% increase in deaths.
New Jersey Gov. Phil Murphy is "very concerned" about surges in other states because "we've lived through hell," he told ABC News' "Good Morning America" on Tuesday.
"We've lost over 13,000 confirmed fatalities to COVID-19 in our state. Over 15,000 if you include probable deaths," he said. "We don't want to have to go through that again."
New York Gov. Andrew Cuomo said Monday he was issuing an order requiring out-of-state travelers from states with rising coronavirus cases to give local authorities their contact information when they arrive. Cuomo said this would help enforce the mandatory quarantine for people traveling to New York from high coronavirus states.
When asked if New Jersey is considering a similar order, Murphy told "GMA," "we'll do it our own way, but were deadly serious about this."
"We knew when we opened our state up we'd take on more risk of transmission of the virus, but there's an added element from folks who are coming in from out of state, from hot spots, and we'll take that very seriously," he said.
New York, New Jersey and Connecticut have a travel advisory in place for states with a positive test rate higher than 10 per 100,000 residents over a week average, or any state with 10% of higher positivity rate over a week average. Travelers arriving in the tri-state area from those states must quarantine for two weeks.
Last week, Delaware, Kansas and Oklahoma were added to the travel list, joining Alabama, Arkansas, Arizona, California, Florida, Georgia, Iowa, Idaho, Louisiana, Mississippi, North Carolina, Nevada, South Carolina, Tennessee, Texas and Utah.
A 14-day quarantine will no longer be required for anyone arriving to Russia, according to a decree signed by the country's chief sanitary doctor on Monday.
Starting from Wednesday, people entering Russia will need to provide a document -- in English or Russian -- that they have tested negative for the coronavirus in the past 72 hours.
Alternatively, they can test in Russia and provide the document within three days. This news followed last week's announcement that Russia is looking to resume international air travel in mid-July.
Russia confirmed 6,248 new coronavirus infections on Tuesday bringing the country's official number of cases to 739,947.
Over the past 24 hours, 175 people have died bringing the total death toll to 11,614.
A total of 8,804 people recovered over the last 24 hours bringing the overall number of recoveries to 512,825.
A group of Miami-area medical experts joined Miami-Dade County Mayor Carlos Gimenez on a Zoom news conference Monday and made clear that South Florida is in a dire position when it comes to the spread of COVID-19.
"Miami is now the epicenter for the virus," said Lilian M. Abbo, M.D., an infectious diseases specialist at the University of Miami Health System and the chief of infection prevention for Jackson Health System. "What we were seeing in Wuhan [China] five months ago, we're now seeing here."
The experts were speaking minutes after Florida announced 12,624 new cases of COVID-19 -- a day after Florida set a daily record for any state with 15,300 new cases.
The experts stressed the need to restrict large gatherings of people in indoor spaces, and Gimenez said the biggest thing that needs to be done is residents following the safety guidelines.
"The reason [for the spike] is us. There's no Boogeyman. The reason is us," he said. "We have to change our behavior. The no. 1 reason is our behavior."
Hawaii Gov. David Ige announced that, in light of the surge of cases on the mainland, Hawaii is delaying its reopening to tourists until Sept. 1.
The plan was to allow tourists who have tested negative for COVID-19 within 72 hours of their trip to Hawaii to bypass that mandatory two-week self-quarantine starting in August. But with the increase of cases in the state and the growing number of cases nationwide, officials decided to delay it by a month.
"I am announcing today that we will be delaying the launch of the pre-travel testing program until September 1," said Ige during the press conference. "The outbreaks on the mainland are not in control and we don't believe that situation will change significantly by Aug. 1st".
Said Ige: "We did believe it would be in the best interest of everyone here in the state of Hawaii to delay the start of the program to Sept. 1. I know this increases the burden of businesses here in Hawaii …we still believe in the pre-testing program and we will take actions to implement it safely."