Until now, health officials said they'd hoped to prevent community spread in the United States. But following community transmissions in Italy, Iran and South Korea, health officials believe the virus may not be able to be contained at the border and that Americans should prepare for a "significant disruption."
"Ultimately, we expect we will see community spread in this country," Dr. Nancy Messonnier, director of the U.S. Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases, said Tuesday at a news conference.
Messonnier added that Americans should channel their concern about the virus, officially called COVID-19, into preparing for its arrival.
Officials said that Americans should continue to practice protective measures -- hand-washing, staying home from work when sick -- while local officials should make sure systems are in place -- teleschooling, working remotely -- should face-to-face interactions need to be reduced. Health care facilities should be prepared to increase telehealth systems and delay elective surgeries should the need arise, they said.
Messonnier noted that every community's response will be different. What's appropriate for a community with local transmission may not be appropriate for a community in which no local transmissions has occurred.
So far there has been no community spread in the United States. Forty-three people repatriated on charter flights from Wuhan, China, and from the Diamond Princess cruise ship have tested positive for COVID-19, and 15 cases have been detected in the United States via the country's health system. Among those 57 cases, only two involved human transmission in the United States, and those transmissions were among members of the same household.
"We are going to continue taking those measures but we are realistic that we will see more cases and as we see more cases we might have to take community mitigation efforts," he said.
If the White House's request for funds is improved, the $1.25 billion will be earmarked for accelerated vaccine development, the procurement of equipment and supplies and to support preparedness and response activities, according to the White House Office of Management and Budget.
"The president's most recent budget called for slashing funding for the Centers for Disease Control, which is on the front lines of this emergency. And now, he is compounding our vulnerabilities by seeking to ransack funds still needed to keep Ebola in check," Pelosi said in a statement Tuesday morning. "Our state and local governments need serious funding to be ready to respond effectively to any outbreak in the United States. The president should not be raiding money that Congress has appropriated for other life-or-death public health priorities."
She added that lawmakers in the House of Representatives "will swiftly advance a strong, strategic funding package that fully addresses the scale and seriousness of this public health crisis."
Senate Minority Leader Chuck Schumer also called the Trump administration's request "too little too late."
"That President Trump is trying to steal funds dedicated to fight Ebola -- which is still considered an epidemic in the Democratic Republic of the Congo -- is indicative of his towering incompetence and further proof that he and his administration aren't taking the coronavirus crisis as seriously as they need to be," Schumer said in a statement.
At the same time, Bruce Aylward, an epidemiologist who led a team of international experts in China, said that the epidemic is slowing in China.
In addition to a falling rate of new infections, hospital beds are opening up and there's no wait for tests at fever clinics, Aylward explained. It's impossible to know if this trend of decreasing cases will continue, but for now, Aylward thinks China's response to the outbreak, which included rapidly building hospitals and imposing strict lockdown measures in cities hardest hit by the virus, is working.
"The implications are that you can actually effect the course of this disease, but it takes a very aggressive and tough program," Aylward said at a WHO news briefing in Geneva on Tuesday.
As of Tuesday, China's National Health Commission said it's received 77,658 reports of confirmed cases and 2,663 deaths on the Chinese mainland. More than 83% of the cases and all but one death were in Hubei province, which includes the city of Wuhan. Chinese authorities have since placed the city under lockdown.
An additional 121 confirmed infections have been reported in the special administrative regions of Hong Kong and Macao as well as Taiwan, with two deaths in Hong Kong and one in Taiwan, according to China's National Health Commission.
WHO experts in China are currently reporting a 2% to 4% fatality rate in Wuhan and a 0.7% fatality rate outside the city. For mild cases of the disease, there's a roughly two-week recovery rate, and for more severe cases, the recovery rate is between three and six weeks.
COVID-19 causes symptoms similar to pneumonia, ranging from the mild, such as a slight cough, to the more severe, including fever and difficulty breathing, according to the U.S. Centers for Disease Control and Prevention. There is no vaccine yet for the virus.
The outbreak of the new coronavirus has continued to spread overseas, with at least 2,069 confirmed cases in at least 33 other countries, resulting in at least 33 fatalities, according to the latest data from the WHO, which has declared the epidemic a global health emergency.
Although the virus "absolutely" has the potential to become a pandemic, WHO director-general Tedros Adhanom Ghebreyesus said it's still too soon to classify it that way.
"For the moment, we are not witnessing the uncontained global spread of this virus and we are not witnessing large-scale severe disease or deaths," he told reporters at a press conference in Geneva on Monday. "Does this virus have pandemic potential? Absolutely it has. Are we there yet from our assessment? Not yet."
South Korea reported another surge in new infections overnight, making it the second-highest national total behind China. As of Tuesday, South Korea's Centers for Disease Control and Prevention has recorded 977 confirmed cases and nine deaths.
The recent spike in cases prompted the U.S. Centers for Disease Control and Prevention to issue a warning on Monday advising Americans to avoid traveling to South Korea. The federal agency raised its travel warning to the highest level for those contemplating travel to the East Asian nation.
The heightened warning came on the same day that officials said a relative of a U.S. service member in South Korea had been diagnosed with the novel coronavirus. In a press release, U.S. Forces Korea announced that it had been informed by South Korea's Centers for Disease Control and Prevention that a military dependent living in Daegu had tested positive for COVID-19.
It's the first time a U.S. Forces Korea-related individual has been infected with the virus, according to the press release.
South Korean Defense Minister Jeong Kyeong-doo said as of Monday there were 13 South Korean military personnel infected.
Partly as a result, U.S. Defense Secretary Mark Esper said Monday that the United States and South Korea were considering scaling back an upcoming joint military command exercise.
Japan has the third-highest national total, when including the nearly 700 cases diagnosed aboard the Diamond Princess cruise ship.
The cruise ship has been quarantined at Yokohama port since Feb. 5 and 695 people on board have tested positive for COVID-19. Three passengers have died, all of whom were Japanese nationals and in their 80s, according to Japan's Ministry of Health, Labor and Welfare.
All those who have been infected were brought ashore for treatment, while the rest were confined to their rooms until the quarantine period ends. Passengers who have tested negative for the virus have been disembarking the ship since last Wednesday.
Clusters of coronavirus cases in Italy and Iran have raised concerns of the global spread of the outbreak.
As of Tuesday, Italy's Ministry of Health had recorded 322 confirmed cases and 10 fatalities. The majority of those cases were in the northern Lombardy region, prompting some towns to suspend public gatherings, demonstrations and sporting events and to close schools, businesses and restaurants.
The initial cases in Italy were linked to Chinese tourists, according to the health ministry.
Syracuse University in upstate New York alerted students Tuesday that it was closing its Florence campus for the semester and helping the 342 students who were studying there return home.
"We believe this is absolutely necessary to reduce the risk of our students being unable to leave Italy due to Italian containment efforts," the school said in a statement.
Switzerland and Austria, which border northern Italy, reported their first COVID-19 cases on Tuesday.
Schools were closed across the country on Tuesday for a second day, and health workers have begun a daily sanitizing of public buses and the Tehran metro.
Among those infected is Iran's deputy health minister, Iraj Harirchi, who is head of the national headquarters tasked with containing the coronavirus outbreak. He had strongly opposed suggestions to quarantine the hard-hit city of Qom.
Meanwhile, a tourist hotel on the island of Tenerife in Spain's Canary Islands has been placed under quarantine after an Italian guest tested positive for COVID-19. The guest, a doctor from Italty's virus-hit Lombardy region, went to a local hospital on Monday and was placed in isolation along with his wife, who tested negative for the disease, public health officials for the Canary Islands told ABC News.
Around 1,000 guests staying at the Costa Adeje Palace hotel have been confined to their rooms while health workers test everyone for the virus on Tuesday. All samples will be sent to Madrid for testing, officials told ABC News.
So far, Spain has two confirmed cases of the novel coronavirus, according to the WHO.
ABC News' Aicha El-Hammar, Somayeh Malekian, Elizabeth McLaughlin, Christine Theodorou and Ivan Pereira contributed to this report.
This report was featured in the Feb. 26 episode of “Start Here,” ABC News’ daily news podcast.
"Start Here" offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, Spotify, the ABC News app or wherever you get your podcasts.